Excellent thread Devil! Great advice from Wolf and all.
I have been a motorcyclist for 40 years but found the transition to bicycle difficult.
Careful "seat time" will change that and I found all Wolf's advice very true.
As for general de-restricting and getting up to speed and fuel efficiency:
1) match the intake gasket (but not the port, a step here is good)
2) sand or cut a "Squish Area" into the cylinder head and sand its gasket surface to get 1mm clearance
3) Some careful widening of the cylinder ports will help. Don't make them taller.
4) port match the exhaust pipe and gasket to the cylinder
5) Tuned exhaust pipes are "Da Bomb" but I found this worked well and is quieter than stock:
http://www.motorizedbicycle.ca/exhaust-system/chrome-exhaust-muffler.html
(quieter, inoffensive looking and made good power compared to other stock exhaust systems)
As well, I'd suggest
1) pedaling at all times while riding
2) shutting motor off and pedaling around pedestrians on shared use trails and in residential areas
3) keep the speed down in appropriate areas.
It is our behaviour that gets us noticed by the police.
Loud pipes, engine only riding, excessive speed, no safety gear, and aggressive driving will get us noticed and pulled over.
It is only at this point that most police will start picking the bike apart for legalities.
Unless of course some previous motorized biker has already soured his attitude toward us.
We are all in this together folks...
Steve