Thermal scope for Vincent but also - how'd he get that scar, does he like being called Vince or Vin, who's his love interest, does he like puns, and what does he love most about space?
From the Mass Effect OC Ask Meme
Thermal scope - How does the character go about reading people? Do they take people’s words and actions at face value, or do they tend to dig for other motives?
All good humor on the outside, but Vincent's not naive, either. If anything, he knows how to use his own unassuming personality to his advantage - by gaining trust, or in other cases, convincing the enemy he's a moron - to dig deeper.
Because while he does believe most are inherently good, he also understands that two people on opposing sides can both believe they are right.
At the same time, however, he mostly just trusts his gut. They've always had a gift for reading people, knowing when they mean what they say, and it's gotten him outta trouble plenty.
As for the other questions:
Vincent got his scar during a skirmish defending the Arcturus relay the first year of his post. They were ashamed of it at first, as though it was a sign of weakness, something Alec would see as proof he wasn't up to the task of being a soldier. But his friends in the unit gave him the confidence to wear such a battle scar with pride. They've acquired other, less visible ones, since.
He's okay with nicknames and they vary depending on the person! Sister calls him Vin. Most in his unit in the Alliance called him Vince. Those in Andromeda refer to him by Ryder or his title. The informality is comfortable, almost less personal in a way.
It's not until they meets an exile named Reyes Vidal that someone very purposefully calls him Vincent again - despite his insistence otherwise - the first since Mama Ryder. I'm sure you can guess who their LI is then, eh? 😏 He's a sucker for that pretty face and whiskey smooth voice. The whole package, really.
Loves puns! He is a big jokester themself after all. Lay a good pun on him and that's the fast route to friendship - especially if you appreciate his in return.
Vincent Ryder's favorite thing about space is the adventure. Sailing off into the big unknown, meeting new species, discovering new worlds, learning about a variety of cultures are all things that have fascinated him since childhood.
He's always ready to meet a challenge head-on and yeah, maybe some of it's a desire to prove themself too. In the end, what matters is he never gives up, never lets the world break him down, and always sees sunrise on the horizon even when those around him can't.