I don't understand your point.
cgi works fine in mod_perl 1 and 2, i've seen no problems whatsoever, but You need to install at least version 2.87 of CGI.pm to work under mod_perl 2.0, as earlier CGI.pm versions aren't mod_perl 2.0 aware. (as taken from the mod_perl2 apace documentation.
for comparibility use
PerlModule Apache2::compat
If you don't want caching in mp-1, don't use
Apache::Registry but
Apache::PerlRun I think it's not needed anymore in mp-2.
"We all agree on the necessity of compromise. We just can't agree on when it's necessary to compromise." - Larry Wall.