You should be able to reuse the intake gasket, as long as you don't damage them. You shouldn't need to drain the coolant (there is no coolant passages in the intake), you will have to disconnect the to small coolant lines on the TB, but you can just stick some 3/8 bolts in them to plug them. Any sensor safe RTV will be fine and only needs to be used to seal around the rubber seals for the knock sensors so water can't get down in them.