I look at this and see another Rhapsody and Rampart mix.
The tactical could work but the numbers (especially availability) seems very high.
The ultimate is pretty much Shiela, and has a TON of bullets. R301 is hugely popular and you want a better one with basically free bullets, taking no space... yeah...NO.
The passive, depending on how it's implemented sounds like sound visualization in Fortnite which is a rather huge pair of steering wheels. Having it all the time makes him a scouting legend close to Seer if not better. And always accessible it makes it even worse + might not really fit with the ADHD theme as concentration also plays part.
Looks and story I don't care for so I won't comment on it other than it seems like we already have it, potentially minus ADHD which you might not notice in other characters anyway.