My suggestion would be to continue to use CPAN and contribure your own modules as you find that some ideas may not have been published as of yet.

As far as becomming a maintainer of different modules, I would recommend this:
If you use a module that you find bugs, want modifications, add functionality, etc., that would be a good time to get ahold of the author. When in contact, you may also express your wishes to maintain more CPAN modules and that you would be happy to make your requests for fixes, functionality modifications on their behalf.

This should be pretty fair to the authors and yourself as well. Be warned though, there are a number of mods that have been in CPAN for some time now, and the authors might be out of date with the Perl community. The e-mail address, personal URL's, etc might be out of date. No matter the case, I would keep the recommendation. It will not only allow you to be the maintainer you wish, but it will also keep your interest since applicatons you maintain will be using the modules as well.