This can result in a lot of abuse. One person can get in with a ton of newbie alts, post a ton of insubstantial posts and then report the newbie posts on their main account.
I don't think doing it in the way you says is worth since positive mod action is required to have the reported post paid. Thus, multiple spam posts from alt-accounts could end up first having them banned then having your main account permabanned for ban evasion, like admin & mods are doing on sig-ad ban evaders recently.
Yes, but you never know how crazy some people are for small amounts of money
