I don't have the time to address each of your points, but you may want to
check out the C translator, dialect, and VM sources for Slate, at:

http://slate.tunes.org/cgi-bin/viewcvs.cgi/slate/src/mobius/c/

for the C-generator, and:

http://slate.tunes.org/cgi-bin/viewcvs.cgi/slate/src/mobius/vm/

for the VM sources (and some extra things like the bytecode compiler).

We already have performed many things to optimize and clean up the GC code
(GC's are pluggable in the Slate VM), as well as for memory structures and
function calls (we already handle inlines as C declarations and can inline
ourselves with a non-kludgy framework). It's not backward-translatable in
an immediate-satisfaction sense, but it might help to see a clearer
version of what's there.

-- 
Brian T. Rice
LOGOS Research and Development
http://tunes.org/~water/