No, you will not have any problems with the RCM mount - the best quality on the market. Unless it got bent somehow or something.
And about the ESC . . . I don't like that mounting location either. One of the best spots I've found is on top of the steering servo. You usually have to make a plate for it to sit on, but it works awesome and keeps a lower CG as well as balances the weight of the battery on the other side. Like this:
Sweet - this is my 800th post!!