First off, welcome aboard! (Full disclosure: C.B.N. is a good friend of mine and plays in a band with me
Ok, measuring resistance- I'm afraid you can't really measure them once they're soldered in to the board (since they are connected to other
parts now, the reading won't be an accurate measure of just that one resistor anymore). You could check the resistor stripe codes against the parts list in the instructions at this point. Kind of a pain, I know..
, I would take that all-important photo of both sides of the board, plus the off-board wiring, and post that up here so we can have a look. Given your battery is heating up (and
no sound at all when engaged), I'm still thinking reversed DC jack wiring could be a possibility. But we'd need to see it.
Discharging caps- Very important in high voltage situations (think: amp building), but I've never even considered the need for that in 9V circuits. I wouldn't worry about that at all.