So I was just watching an NCHammer23 video and when he was talking about Guy noticing TenTen has some skills in storing and summoning jutsus but was largely useless compared to other ninjas in her age group, I had a lightbulb go off in my head about 2 different ways in which TenTen could have been made stronger. Starting with Flying Raijin.
I know, I know, it's an incredibly chakra-taxing technique, and I don't think she'd be able to do it nearly to the extent that it's inventor and Minato could. Maybe 10 times per fight to make it believable. But think of how well it would complement her kenjutsu-only fighting style. Allow me to explain.
Minato used it largely for killing enemies up-close faster than they can react. Yeah, maybe TenTen could use it that way, but I think it would make more sense for her to use it in tandem with long-range throwing weapons. Think of her as essentially a ninja sniper that could teleport to another place on the battlefield as soon as enemies get close to her. In a 1vs1 fight this might not work out all that well in her favor, and especially not if it's just her fighting multiple enemies since she'd probably use up her chakra teleporting awayfrom enemies in no time. But keep in kind that she was usually teamed up with *3* close-range fighters, basically all 3 of them being monsters (yes even Neji, he was just a more defensively-oriented taijutsu specialist as opposed to Guy and Lee). All 3 of them would be amazing distractions on the battlefield to draw attention away from TenTen so she can concentrate on her throwing-weapon sniping capabilities. And Neji with his nearly 360° of vision and 800 or so meters in range in any direction, he could also be able to keep an eye on her situation and make sure enemies don't get too close to her. At least he could've done that for her until he died in the 4th Great Ninja War (rip).
Now for the other improvement: Medical Ninjutsu. Reminder, thanks to Tsunade, every team is supposed to have 1 medical ninjutsu specialist. Guy and Lee definitely wouldn't fit that role, and maybe Neji could but he's *not the best* for that role on that team, as he's still a close-combat type. Another reminder, Tsunade laid out the rule that medical ninja are not supposed to get up close and personal (unless you have that seal on her forehead thing but I digress). This suits TenTen perfectly, since she's a long-range fighter type. She stays out of sight and attacks from blind spots while the rest are drawing attention away from her, until her medical ninjutsu is needed. Someone on her team gets hurt and needs to be healed? She heads in and heals them, and the other 2 can defend her and the injured during that time.
But I'm not stopping by keeping the 2 improvements separate from each other. If she has both of the added skills I mentioned at once, she'd be able to use Flying Raijin *and* medical ninjutsu in tandem. Imagine not having to rush in and fight through waves of enemies to heal your allies, because you're able to just teleport to your injured teammate's side with a seal you personally placed on them before, saving precious seconds or minutes for treating them that could otherwise possibly cost them their lives.
And just like that, you make TenTen a really useful ninja. Not a powerhouse, and not someone that is made for 1v1 combat like a lot of the others, but she becomes one of the best support ninjas around, combining long-range attacks (and not the flashy kind that might be detected before they hit, btw), unpredictability and maneuverability, and basically being the team's white mage. And she *still* has her main area of skill and expertise in throwing weapons, she just has other skills to complement that.