Sounds like the consensus is that I've got a couple of unrelated issues:  weeping from the fins, and the cylinder 2 & 3 problem.  Hey, one problem at a time would be too easy!  And I agree that not pulling the engine is definitely preferable.  
Any good tips on testing my coils w/o an actual tester?  That's what the manual calls for, but of course my garage toolbox didn't come w/ one.  
  AJK: thanks for sending thank link along.  i'm going to give the fins a good scrub down and see if I can trace the oil leak.  it's still pretty minor (weeping, not dripping), so unless it gets worse I might just throw some cotton rope btwn the fins (if that's where the oil's coming from) for the time being.  I'm guessing that wind won't dislodge it?
Ekpent:  good call.  i'll file the points down a bit to get rid of that divot, & try some new spark plugs.  Z1 has a points/condensers kit for $16, so maybe I should just swap for the new ones? 
grcamna2:  also a good call.  i've never adjusted my valves or cam chain, but it's time i learned!
markcb750:  oh man, keeping the rpm's below 5k would be tough! my first few motorcycles were modern sportbikes, so going slow and mellow isn't a habit i've ever learned.  

  i just bought another gallon of simple green for cleaning, along w/ some fine brass wire brushes and a stiff nylon brush.  if those fail, i'll grab some brake cleaner and keep it away from any open flames!