No you can't run an intercoller or BOV in a "draw-through" (carb in front of turbo) setup. This is because the coller with have air AND FUEL running through it, same reason for the BOV, it'll spit out a nice stoich mix into your engine bay.
Internal/external gate makes no difference to weather you can or can't run a BOV.
Yes you can run a carb after the turbo - search for "blow through".
You can run it on the stock compression ratio, with 10psi. You just need to adequately tune it mainly in the timing.