Hi Jack,
Chameleon tgp/mgp submitter is a gallery submitter so with the tool you can submit galleries to all kinds of TGPs/MGPs (also to those accepting non-partners as well as to those only accepting partners - both free and paid);
As for the sites only accepting gallery submissions from their partners - if you would like to submit your galleires also to these sites you would first need to become their partner. And in order to become their partner you first need to apply for partner accounts - obviously by sending them some information about you, your galleries, with some references, etc. And this can be done using Chameleon PA requester.
So basically, Chameleon PA requester serves for requesting partners accounts to the sites accepting partners.
If you're new to gallery submitting I recommend you to start with Chameleon tgp/mgp submitter first, even without partner accounts. You will be able to submit your galleries to the sites also accepting regular webmasters (non-partners) while the sites only accepting partners will automatically be skipped from submitting.
And once you become more experienced - when you get some more examples of your work (like e.g. your submitted galleries, etc.) you might try to apply for partners accounts, with or even without Chameleon PA requester

All the best,
Joan