I suggest you just set it up (maybe call it basicaccounts if it isn't already taken) and then just let all your flist know. I will let all mine know and ask everyone to circulate it. But you should set it up so anyone can post so they don't need to join to do so.

You don't really need to do much monitoring, just let people know what they should do in the way of backing up and deleting their comments, posting the name of the journal and a contact email address.

I'd also suggest that you indicate in comments somewhere that people with Plus accounts have priority over someone who already has a Basic account.

Mac (typing from work, no signed on)