Rick,
>Looks like P(revious), N(ext), R(eply), and M(ap) would be available without interfering with the IE menu. I don't know what other implications this might have. Other possibilities might be Ctrl+PgUp for Previous, Ctrl+PgDn for Next, Ctrl+Home for top-of-thread, etc. What do you think?
ACCESSKEY works only with single-digit alphanumerics, I think, and requires the ALT key.