Interested in playing a Bone Gnawer theurge, urban shaman type character.

Two questions though. 

1) Will there be OP GM characters fee-fi-foo'ing about or will the game be player driven with the possibility of a wily player even usurping the Prince and taking over?

2) Can we introduce other supernaturals as side characters or allies? For example, it is common for the Bone Gnawers to have dealings with wererats who in WOD infest pretty much every major city underbelly. Can I introduce them as contacts for my character and involve them in my story to a limited degree?