Regarding the AddOns to "Geocacher":
We are regarding all those cache types as special types that are either unique (or almost) or not available anymore/at all times. One could argue to add CC, HQC, HQ Block Party to "Social Cacher", but we have already 4/6 slots used for AddOns on that badge so we only have 2 slots left. The Geocacher had none used, we had 6 AddOns and 6 free slots so it was the obvious choice, and it makes sense too, if you regard them as special types.
Locationless is not an event-based cache per se as there were many many locationless back then, all of them count for the AddOn now, too. If you don't find GC8FR0G this year but have found a Locationless back in the time, you also get the AddOn.
Community Celebration AddOn to "Event Host" is a good idea, I think it is on the list, because I don't know why it should not, maybe we just forgot. :D