They should not even have the ability to lock or self moderate their threads.
Locking threads is necessary no matter what rank you are.
Self moderated threads could definitely use some tightening on the rules though. Maybe even full members or above? The problem is that hacked accounts use these threads to take out loans so rank becomes irrelevant. I don't really see the need for self moderated threads ever. For every legitimate case there are 9 illegitimate cases.
Blocking PMs though? Who cares. They're using a newbie throwaway account with a throwaway email address. You sending them 50 PMs a day won't get your money back.