I'm not going to argue all the points because I tend to agree that the RMT spam can be a bit extreme and reporting the player doesn't seem to be doing anything because hours later, they're still there doing the same thing.

However, your #1 item is not RMT in anyway. Mercs are offering clears for gil, in-game currency. RMT is "Real Money Trading". No real world money is changing hands in this instance. While I don't agree with the practice and won't use it, if you have nothing better to do with your gil and are willing to pay someone in game to do it for you, have at it as far as I'm concerned.