I agree with Onix. Lolicon is an essential part of gurochan, and honestly there's just not much left without it.
As a matter of fact, even though my collection includes just as much non-lolicon as lolicon, I can't remember the last time I have found anything interesting here that wasn't lolicon.

I think gurochan can come back from a temporary ban for new content, that's just like a long downtime for a part of the community, and this site has come back from long downtimes in the past. However, once you start deleting content, it's over. I don't think this site can recover from that.

What needs to happen is a permanent solution for the CP spammer, and this ban will probably not change anything about that. A technical solution where an account is required at least for posting pictures would be the best way to do that.

Of course that takes time. I think the site might be better off longterm if you just take it down until you find a new host and this technical solution is implemented. If you go this route you are currently on, you are going to lose a large part of the community, probably for good, and I think as long as the spammer is around he will cause more problems for you.