I thought this was supposed to be supposed to be a stand alone Venom film? IE, without Spidey...(could be wrong about that though).
As for choosing Tom Hardy. I'm reserving judgement. He is an awesome actor, so it'll just depend on how the writing and directing take it.
EDIT: Also, it's my understanding that Spidey himself is the only part of the Spider-Man comics that Sony is allowing Disney to use in the MCU films. So Venom and any other movies Sony does won't actually have anything to do with the MCU. (Just like Fox and the X-Men.)