Is Trap Expert worth it? I have Quick Tinkering anyway, so Trap Expert would be more of a QoL thing I guess. Also useful for setting massive trap zones fast(er) in some areas.
Extra stat points - is getting Agi above 7 worth it? I realize that it indirectly boosts crit damage through Snipe
Special Tactics - worth it? Useful for burst I suppose, but very situational.
Snipe - haven't used this on my old crossbow build, and with the build so focused around crits I'm wondering if it's worth picking up. At this point I'm also wondering if it's better to use Smart Goggles (if taking both Aimed Shot and Snipe) or Seeker if only going with Aimed Shot
Goggles - see above
Crossbow - which type and modules are generally best right now? I've done a cursory search through the wiki and it seems like Zephyr with Anatomically Aware Scope and Super String would be the best option. Or AAS + Pneumatic Reloader if using Adrenaline syringes.
I played without Trap Expert and i never though i really need it. If you use traps mainly in combat with QT, enemies will not have enough time to detect them anyway. I'd say that for a build that is pretty feat starved, it's a waste of feat slot.
Your overall build is pretty solid, though i would change Interloper for Paranoia. With new creatures additional detection is always welcome and +5 init will help you with arena and some other fights.
My build uses 7 Agi and 7 Dex. Exchanging 3 Per for 3 Agi is more of a matter of taste. Though if you won't use Blitz (and as a crossbow user, you probably won't) i'd say you aren't getting anything special.
Main tactics for crossbow user is alpha strike with special attacks and electric bolts, so while it seems that Special Tactics is situational feat, you'll use it very often for the duration of the game.
Just because you focus around crits doesn't mean you can't use Snipe for great damage. You spend one feat and in return you have almost 100% guarantee that one of the enemies is dead after you first round. All it takes is heavy investment in stealth, which is a good investment by itself.
As for goggles...well both ways are pretty effective. With both i finished hard difficulty without any issues. Though if you want to go crit chance route, you'll probably need Recklessness feat too.
Your main weapon would probably be Cyclon with Pneumatic Reloader, since it is possible to get 4 attacks from the uase of adrenaline. Second component will either be Super String, crit damage scope or scrit chance scope (if you go for crit chanse route). IIRC crit chance scope gives you most DPR, but SS version is more reliable with damage output. I made some calculations in the past, but i don't remember specific numbers. Second weapon can be either Zephyr with super string and crit damage scope (crit damage on this with Critical Power, Sharpshooter and Bowmen is very high, though it may be overkill) or Monsoon with super string and crit chance scope.
Overall i say that with critical chance route you have better damage output outside of alpha strike phase. Had much easier time with Tchort.
Main tactics for crossbow user is like this - find enemy -> find good position -> manually start combat -> activate Special Tactics -> activate NVG -> use Snipe -> use Aimed Shot -> Use special bolt (possibly electrical for stun) -> if there are enemies alive and not stunned, use adrenaline shot -> use another 2 bolts to stun or kill them -> finish stragglers. It pretty effective even if after certain point a bit boring. Crossbow is pretty good when you can use it like that, but not exactly stellar when you can't.
Pro tip: Stack up on electro bolts. They are most useful of the bunch. You don't even need to craft them, just buy them from merchants in every merchant run. Honestly, i probably use them more often than regular bolts, so you can never have too much of them/