About competitive discussion, the closest thread to that is this one :
About tips and tricks, it's true that right now there is no guide at all.. I think it's because multiplayer is not out yet.
When MP comes out, people will start searching for the optimal ways of playing GRIP, and will come up with guides eventually.
It could be a good idea to have a Tactics subforum somewhere where people exchange their tips. I guess we will see later on when people are willing to share their secret strategies