1. Why is my single 8. notes so big, and how do I change it to the size
similar to the other notes?
I'm not clear on the problem here. I don't see any outsize notes. Are
you referring to the ones with flags rather than with beams?
2. How do I change the size of the text under the grace notes, so they
are
smaller than the other text.
markH = \markup \small "H"
markV = \markup \small "V"
c16_\markH
c_\markV
------------------
There's probably a better way, but that does it. If the letters are
still too large, use \tiny instead of \small.
Geoff