re: STA - you can adjust around a non-ideal STA but it would be better to be in the middle of the range. So instead of slamming a saddle all the way forward on the rails on a zero setback post, get a steeper STA. Or, if you're tall, instead of jamming the saddle back on a huge setback post, get a more slack STA. For saddles it can reduce stress on the saddle (they don't seem optimized to be clamped at one end or the other), post (having a saddle hang way forward or backward doesn't seem good for the clamp), or even increase comfort (pushing the saddle back allows it to flex more).
In another "stay in the middle of the range" example. I use the 4.5 degree Keo cleats. I try and have the cleats set up so I have about the same amount of float in each direction. I could easily ride with just, say, 1 deg one way and 3.5 the other, but it doesn't allow the same amount of float each direction. I've been meaning to adjust my left foot ever since I unclipped while pedaling seated, but I haven't. I should do it before this weekend's race.
Re: cranks. I use 175s. I'm away from my tape measure but I think my inseam is 73 cm. It's really short. I find the 175s work really well for overall riding - long rides, hills of all flavors, etc. The only place it loses out is in top speed, but my top speed is down at least 10-15% (on equal length cranks) so I've given up on top speed. Now I want to finish races/rides with the group, and long cranks really help me with that.
I think I'll be switching to 170s for the summer (because I have 170s on the track bike - but the track I go to just got weirded out - NE Velodrome). If I don't race track I'll keep the 175s on.
If I go to 170s for the summer, I'll raise my saddle 5 mm. I'll let the raising bit move it back too, so maybe a net gain of moving it forward 1-2 mm. I'll leave my bars as is.
When judging what I use/do, try to keep in mind that "racing" is just riding. Fine, I race, but that doesn't automatically discount what I use for normal riding. My racing is no harder than a group ride, and in fact I get dropped from the local shop's ride all the time (and there's one, maybe two racers, Cat 4 and Cat 5, that do the rides regularly - the rest are explicitly non-racers).
Although long cranks "help" me race, I put them on because they help me go up normal hills better (less than 10% grade). If they didn't help me go up hills easier, they wouldn't help me race.
cdr