i am also new to whiteblocks, here is what i have learned sk far. im told head bolts are single use for these too, so a set of them.
special volvo goop for the cam cover, no gasket. doco says best to use a roller to apply it evenly and to avoid squishing it into the oil gallery. Berrys posted me out a tube of genuine goop and some seals, though seals would be in a vrs kit.
sounds like you are all over the timing belt, i just replace them on everything so i know they are new. not sure on the water pump, cannot comment.
depending on the generation of b6304 the thermostat may be down inside the timing belt, this may be worth replacing, again i just replace the thermostat on all of mine with a genuine unit so i know it is good, much easier on a b230 though ;-)
one thing I was told, a little too late, is to leave the cam gears bolted to the cam, or carfully mark up the alignment as the holes are slotted and there is a good 5 deg each way of adjustment. if an early one check the cam angle sensor at the back, mine had a deteriorated connector that crumbled when touched. bosch unit from fcp was not much coin.
careful disconnecting the coil packs too, they will be super fragile by now and fall apart if you stare at them for a few seconds, or breath deeply in their direction. also, normal best practice, blow out the plug holes with air prior to removing plugs, it prevents rubbish falling into cylinder.
hope this helps.