Transition Dirtbag, Kona Roast 2002 and specialized BMX
No. I run shimano front and sram rear for example. You do 'generally' have to matchup the shifter with the same type of deraileur, but even then Sram offers the attack series (I think thats the name) which works with shimano.
And yes, as far as I know all front deraileurs will work with your crankset. Only thing that matters there is tube size, top or bottom pull and if, potentially, you have an e-type derailuer.