ok, everything seems to be great now. just took a nice long ride, and the past few weeks it's been near perfect.
things i have done, and what i think the problems were:
made sure the petcock wasn't leaking. made sure my floats weren't sticking. turned out to be my overflow tubes. shortened them and routed better, no obstructions.
i think most of my 'gassy oil' was me overthinking things, but i think the rich state of tune was contributing to the smell.
the main culprit, as far as i can tell, was my breather tube being routed improperly (pointed slightly upwards instead of down), so that any small amount of condensation couldn't drip out. and TwoTired nailed it, i think...i wasn't riding the bike long enough to really warm it up (once the weather cooled off) and burn off all the condensation. combined with the tube not being able to just 'drip' excess out, i was noticing a lot more smoke being burned off.
thanks for the insight (and good kiwi jokes!)