Pretty sure I can cut somebody off in mid sentence if I'm here monitoring all the time, which I won't be. Potentially and realistically somebody could rant all day and I might not see it until I looked at the blog that evening.
We can let anyone on that we choose. How that happens is I put the name and email on an approved list. Others could see the blog (I think) but not post or comment.
The mechanics of getting a name on is easy, the decisions as to who gets on and who gets blocked or yanked could be harder if we can't agree.