I think you misunderstood on the resistor/FCD thing. The idea is that since the MAP pin comes straight to that resistor from the connector block, you would wire the FCD in there, meaning you don't have to cut up the main ECU loom. The resistor wouldn't be removed, it would be put back in-circuit along with the MAP in/out of the FCD.
If the ECU had've had wires coming from the connecting block onto the PCB then I'd have cut one of those instead of considering removing the resistor.
I sort of agree on the moisture point, but considering that now, I would just replenish the foam stuff around the edges. It's basically this stuff:
http://www.uk2sucks.net/foam.jpg