NodeBB-ActivityPub Bridge Test Instance

No and No.

I know that explaining ActivityPub with no grounding in reality is a tradition. But can you please not do it when replying to me?

I think Activities without a to field, see here, are one of the oddities being allowed by ActivityPub.

I think they are allowed due to splitting ActivityPub in S2S and C2S. However, I'm not sure. It just feels odd. Of course, they might also be allowed because the ActivityPub authors believed in keeping track of the processing history of an ActivityPub, so one would have a record of the inbox being used to receive the activity (maybe even the http signature being used).