I think OP is actually understating the case with some of these.
1. During his first escape from the tower, at the age of 12, he “saved the life of Bann Ferrenly,” for which he was awarded Fox’s Pendant (which comes equipped with him during Awakening; the age is specified in World of Thedas, vol. 2). During another escape attempt, he successfully swam 13 miles across the channel and stayed free for weeks. Canon is weirdly contradictory on the number of escape attempts though. In Awakening, he says, “I escaped from the tower seven times. After the last time, they put me in solitary confinement for a year.” WoT v2 says, “Anders endured several more years in Kinloch Hold, before making his final escape. After his sixth escape attempt, he spent a year in solitary confinement… Shortly after emerging from solitary confinement, Anders escaped again.” Yet his DA2 codex reads: “Anders was still a boy the first time he ran away from the Circle. Recaptured and returned dozens of times, Anders was still considered only a reckless scamp by First Enchanter Irving.”
2. During his 6th escape, he not only survived on his own but apparently managed to track down and make contact with a mage sympathizer (or perhaps a network of mage sympathizers?) in order to track down and destroy his phylactery for next time. Given that he grew up on a farm before being taken to the Circle, it’s remarkable how quickly he learned to navigate urban environments. By Awakening, he even half-jokingly warns the Warden to beware of fraud in the Amaranthine marketplace.
3. Given that his first escapes occurred prior to his Harrowing, he was also risking Tranquility (which was used punitively in Kinloch Hold) — according to his DA2 codex and WoT v2, the only reason he wasn’t made Tranquil may have been due to Irving’s protection. In Awakening, he explicitly expects the Templars to eventually accuse him of blood magic and kill him (which is what happened with Wynne’s apprentice Aneirin, after all): “Eventually, I’m sure they would have branded me a maleficar, true or not, and executed me. The problem is that mages are tolerated. barely. It’s like you need permission to be alive.” (On a side note, it’s worth noting how he easily he understands the forces driving Circle mages to blood magic and how at this point he seems to be at least considering the possibility of turning to blood magic. Even in DA2, when he acquires Justice’s fanatical hatred of anything demon-related, he still retains some sympathy for blood mages who did what they did in order to defend themselves against the Templars). It’s interesting to contrast his cavalier and defiant attitude towards the bad things done to him — the casual and even joking way he refers to having been regularly beaten, called subhuman, locked in solitary confinement for a year (which is wildly downplayed in his own recounting, considering that he neglects to mention how his cell was in a cold lightless dungeon, strewn with the blood and body parts of previous victims, and contained nothing but straw to sleep on), and so forth, combined with how he calls himself “lucky” — with just how devastated he is by the suffering of other people. The incidents that cause him to break down emotionally are seeing Karl turned Tranquil and begging for death, seeing another innocent victim about to be turned Tranquil (and probably sexually assaulted), and harm or the possibility of harm to innocent bystanders (e.g., Ella during Dissent).
4. Considering he refers to recent beatings, he may have been injured when fighting the Darkspawn for the first time (on the other hand, if he had healed himself with magic before then, then he may have been fighting while low on mana). Also, he’s apparently able to easily dispatch the Darkspawn that killed a whole group Templars guarding him.
6. He sets up his free clinic long before getting involved in Kirkwall’s mage underground. Also, his healing skills are wildly impressive and quite broad — he apparently fixes broken bones, delivers babies, revives comatose patients, cures multiple infectious diseases including STIs (which depending on the type may include those that modern medicine can’t take on; in any case, no STI could be successfully cured until the discovery of penicillin in the 20th century), and so forth. The only cases he explicitly states he can’t cure involve the Blight (e.g., Bethany or Carver’s Blight infection in the Deep Roads; Bartrand’s Red Lyrium-induced insanity, which he can only temporarily alleviate) or someone already being dead or undead (e.g., Pol post-varterral-attack, Leandra post-decapitation).
7. He actually spends far more time and energy on his clinic than fighting for mage freedom. He starts up the clinic as soon as he arrives in Kirkwall, quickly attracting crowds, and continues it even after dropping out of the mage underground post-Dissent. Moreover, he’s providing free services and collecting donations to help refugees when he could have instead sought money to fund the fight for mage freedom (which surely could use every penny it can get), even as this healing work is putting him in serious danger. Given the number of brothel customers and that even the Viscount’s seneschal will seek out his help, it’s not as if there wouldn’t be funds to draw upon if he wanted to. He also indicates the Templars knew he was in Kirkwall by Act 1 (given that he refers to them intercepting his letters to Karl). By Act 2, he says of his clinic, “The templars have become more active in their hunt for me. I won’t be able to stay here long.” That they have been hunting him for a while is also confirmed by Cullen if you try to turn Anders in after the Justice (Act 3): “I have already warned both the knight-commander and Elthina about the rebel Anders. We sent a force to apprehend him in Darktown, but the location we were given had been abandoned. We will be sending a force to apprehend him in Darktown soon.” Banters with Varric also indicate that the Carta had been attacking/threatening his clinic until Varric did something (??) to get them to stop sometime in Act 2.
8. It’s also interesting to note that Justice was the one who sought him out and pushed him to take on the cause of mages — Anders was initially reluctant and mostly interested in self-preservation. Something about Anders specifically attracted a spirit of Justice and inspired it to become his champion. In the short story, it appears that Justice was the one who initiated and pushed for the merge, saying, “It is time. You have shown me an injustice greater than any I have faced. Do you have the courage to accept my aid?” This is while Anders was being stalked by Templar agents and thus in serious danger should he accept.
9. Anders was working for the mage underground at a time when the “knight-commander has declared supporting apostates a hanging offense.” Ser Alrik had planned to turn him Tranquil in Act 1, and Anders openly fears that capture could result in him being turned Tranquil as well, which is not only horrifying at an individual level but would put the rest of the mage underground and his friends at risk (the latter for having helped him when doing so is a capital offense), considering that Tranquil are easily made to divulge any information and betray even former loved ones. The reign of terror continues long after Alrik’s death too. In Act 3, if Hawke says, “I can’t even imagine how difficult it is to be a mage here now,” Anders bluntly replies, “It’s easy for most of them. They’re long-since Tranquil.”
Here are a few of my own additions:
12. It appears that Anders can understand ancient Tevene. In Justice (Act 3), he says, “I’ve spent the past three years researching the methods of Tevinter magisters,” and while this alone is ambiguous and could be dismissed as part of the endgame ruse, his Act 3 codex states (if Ella was killed during Dissent), “Anders has taken to spending long hours cloistered with ancient Tevinter texts.” Dorian states that ancient Tevene is incomprehensible to most modern Tevinters, while knowledge of it is considered a sign of sophistication among the magisters (Fenris apparently knows a little, which he may have gleaned from Danarius and his buddies).
13. In his short story, a newly-possessed Anders is able to singlehandedly take down a whole group of Templar infiltrators into the Wardens, including shrugging off a sword through the chest as mentioned earlier.
14. If Bethany or Carver get infected with the Blight, he manages to track down a group of Grey Wardens in the Deep Roads and convince them to take the younger Hawke on, despite the Wardens’ initial hostility.
15. Hosting a spirit makes him immune to Tranquility, which seems to be every mage’s greatest fear, although he clearly doesn’t realize this ability (considering that the cure is kept secret by the Seekers).
16. He’s apparently able to replicate the Qunari gaatlok (which is elsewhere stated to be rather difficult to do) on short notice, despite having no training in this area and no prior experience with explosives or non-magical weapons. In DAI, Rocky (from Bull’s Chargers) admits he blew up the shaperate by accident while trying to do the same.
17. The “electricity thing”
