Honda Head Unit - better reception, check.

Power booster - check.

Chilton manual useless for pinouts - check. (Where did you find pinouts online?)

Giving the service personnel religion - check . Seriously, if you can locate a service manual or get info from your dealer, go for it. I will say that the Acura dealer in town is phenomenal.

S2000 Antenna - had no clue! I'll have a look. Smaller yet more powerful? Amazing. Now where am I going to find a machine screw et. al.?