I do not particularly see any issues with your submission, [@LeeRoy]. As I stated before, your character is more or less at odds with the world for better and worse alike and archaic weapons are, other than in parts which can be easily crafted by even low level equipment now, rare. Ammunition as that being less effective and rarer still, with most caches coming from the wastelands where the nomads drift. Now of course said weapons are still dangerous, but as long as you are not expecting to tussle with chromed up street boosters up close and personal or expect non-armor piercing ballistics to do much, there really is no issue. No one here among the players is a combat machine either and the majority of those are left to non-player characters, namely the Night City Police Department and any big name corporation solos.

Drugs and chemical stimulants are in no short supply either, so at least he will not be made irrelevant despite his lack of enhancements. Just be forewarned of having Yancy's goods cut with something crazy or them attempting to hook your character on something weird and exotic, the typical sorts of threats drug addicts of the dark future would face. But for motivations? I would say there is enough to work with that he is not too disruptive and he's lucid enough to realize that unlike outside, messing with the wrong people here is a surefire way to end up a pawn in their game a lot faster. Essentially in-character reason to not fly off the handle at slightest provocation.