~snip~
I've received 12 messages for a $10 loan. How many ppl did he ask ?
I personally haven't received any, but in your case it's no longer about asking for a loan but about blatant harassment - and in that case you should have reported such a PM to the admin.
You are right that it can't be an exit scam because even if the 8/10 people would accept the loan request then the amount would be 100$ if the amount is on average 10$. The amount could be earned in only 2 weeks. In this case, I do not think there is anyone who is in a signature campaign and the earnings are good based on the loan amount and would not default that.
I completely forgot about the sig campaign, but that also supports the fact that it is probably not an exit scam, unless that person does not think logically and just wants to collect as much money as possible and disappear.