Hi mate, good to see another aussie on the board. I got my motor from ped-bits, and it is awesome, nothing shaking loose, only adjustments is some clutch cable stretch.
My advise is to give the motor about 400 kms and see what it's like, and then you have a better feel for what improvments it might need.
I used Penrite HI-Per semi synthetic oil at 24:1 for the first 5 litres, and then 32:1, and I've found no smoke or carbon build up. Use a NGK b6 plug, and you should have easy running
\edit to add.. I took it easy at the start, to see/hear if anything was loose or dodgy, then give some stick around the neighbourhood to work the motor. Then take it to the hills and work the motor hard, and my motor is going great. Max speed is 45 km/h, with 26" wheels at 80 psi, now the motor is winding out and revving hard, so I've hit a wall at max speed, but the torque keeps building.