Yes I can put it as collateral however in that time can I still access my account as I have some things I would also like to get done. Also if I put my account as collateral will the person holding it be able to read my private messages and alter my stuff in any way?
Yes, of course, the person holding the account will be able to read through your private information and change things
1; however, you won't, because your account would have no value as collateral if you could access, and potentially recover it, unilaterally.
1 - likely password and email, in order to secure the account.
If op signs a message with an old quoted address stating the detailed loan terms and information, the lender can send the message to a forum administrator to stop
any account recovery attempts.
I still doubt that it is worth lending though, as the collateral needs to worth 10% more than loan value.