Ideally, it would be nice to have everything working. You are right though, I don't care about clicks, so that's not a priority. From what I understand, Verizon phones on Cricket's network function just like you described (ie without web access and MMS). It is a shame to lose MMS, and it would be really nice to have it. If anything, that's what I'd like to have aside from the standard text and talk.
Is anybody actively working on configuring the A990 for Cricket? What utility would someone use to edit the settings, QPST? Simply knowing it isn't a hardware or provisioning issue that prevents MMS from working would give me hope that it can be done. That hope, and some familiarization with the tools and internals, give me the urge to get my hanRAB dirty if/when I switch over.