Okay..so this is a tad embarassing...after switching out the following:
1. Large Chainring
2. Chain (from slightly used SRAM to brand new Shimano
3. Cables (pretty worn)
4. Little twisty thing (sometimes known as a 'barrel adjuster')
My bike finally works again! I'm quite certain now, that it was just the little barrel adjuster that was broken! I noticed it being a little 'loose' during the sea otter road race (when I was dropped and had nothing better to think about except why my bike wouldn't shift properly), and I just suggested that it be changed out after numerous other things had not worked. What was happening is the following: The bike would perform perfectly in the stand, and the cable could be adjusted correctly and all shifting would work fine. Then, a few shifts into the race it would stop shifting (i.e. the barrel adjuster was not holding the cable tension and it would slowly change (i.e. shorten) throughout the race), causing immense frustration from me. And then to compensate I would slam the shifter and because I was worried about it not shifting and I had the stop set too far out, the chain would throw right over the top (I have a compact, and a standard derailleur, so there is a gap between the chain ring and the derailleur--a gap that a perfectly tweaked chain can sneak through)! It all makes so much sense now. I have a brand new barrel adjuster (free from LBS-thanks Dave) and all is well!
So now my bike works perfectly...and I am trying not to think about what those races would have been like if I had had such nice crisp shifting then! I do think the Shimano chain ring and shimano chain did improve the shifting as well (although my bike does look silly with shimanos titanium-y looking chain ring, vs. the black carbony FSA crank...).
I will chalk this up to in-experience...and hope that everything I have learned about bike drivetrains will help me or someone else some day! And I'm sure that my trusty bike appreciates all the TLC it has been getting--it has been spotless and sparkling for weeks now!
Ranting about it made me feel better :-)