Welcome to racing... its a whole different world but at the same time it's not, the principles are the same after all!
If I may go through your points:
1) It's a helmsman/tactician thing... what, you can't go from nothing to a kite full and drawing the instant I begin to even think about it?? what's wrong with you?
2) You're either in an insanely competitive fleet (by that I mean evenly matched skills between boats), or your perceptions might be a bit off. Clean starts and boathandling are very important, but the one boatlengh difference between a good set and a perfect set isn't gonna make a lick of difference if you lost 10 boatlengths on the beat because your jib trimmer tacks like a granny, your helmsman pinches, or your tactician blew it and missed a shift.
3) An duck begun well back and missing the other boat's transom by inches is way faster than a crash tack!!
4) Wouldn't really be racing if it was the same all the time now would it?
5) & 6) Common problems... you may want to find yourself a new skipper.
7) Pretty much.
8) You may want to review 5 and 6, or maybe the crew just needs more time together - a competitive well-sailed boat is generally a fairly quiet place.
9) Usually the dude with the "tactician" nametag
Being the boat "know-it-all" is pretty much a job requirement, being right more often than a magic 8-ball is not.
10) Meh, trim is trim... what do you mean?
11) On a 105? What's the bow guy even do on a 105?
To be fair I don't sail on sprit boats all that often, but I agree that I'd rather have a rockstar up there than a newbie on a sym boat!
12) Tough point, sometimes it's a jerk helm, sometimes its a crew work issue. Most boats I sail on are pretty quiet, but we've been together for a while and know each other's "moves" so to speak, and there's a fair amount of trust involved (that you'll do what you do when you need to, and if you're doing something, there's probably a reason).
Final point... good! If your only job is to trim main, then you should just be concentrating there and not sightseeing, unfortunate but true. Kinda sounds like your helms need to be doing more driving and less other stuff as well... every little thing that takes concentration away from watching the luff of the jib will ultimately slow you down upwind, and downwind watch your angles and listen to your spin trimmer.
Glad is sounds like you're enjoying it... trust me, it's even more fun without the yelling, and usually quicker too