Couldn't spot guidelines on this.. where/how would one submit tweaks/fixes to one of the themes included with ZP? (*in my case Stopdesign, but applies to any)

Just create a Trac account, upload to..
http://www.zenphoto.org/trac/wiki/ZenphotoThemes
.., and drop a note here?

Thanks in advance :)

Track is the place--http://www.zenphoto.org/trac/newticket. You will need to create an account to submit a ticket, though. No need for a note here. We monitor ticket submissions.

awesome -- thanks :)