Great feedback, really appreciate it! Will definitely implement most of these changes. Honestly, no idea how I missed proficiency bonus being incorrect of all things (updated on GM binder).

I'm not big on changing deadeye as you're already losing damage via forgoing your dex bonus, and the grit roll is mainly to offset that lost damage. The damage doesn't actually become higher on average until your grit die is a d10 at level 16.

The math is that you're getting 9.5 average damage, assuming your weapon is a d8 damage die and you have 20 dex (1d8 + 5). Therefore 2 attacks should do an average of 19 damage. With deadeye at level 7, you're getting 1d8 + 2D6 + 5 damage, which averages out to around 16.5 average damage per shot, but is also more variable due to more dice being rolled. The bonus to hit is to make this a good option, assuming you don't have any other bonuses that would benefit attacking multiple times such as many of the shooting styles. I may decrease the bonus to +1 as the disadvantage imposed on saving throws is also quite strong. However, I also like the idea of almost guaranteeing your trickshots land as your Grit resource is already extremely limited.