Here is a link to a manual which will take care of most of your enquiries.
http://aerox.us/roketa/arrow150_engi...ice_manual.pdf
As to breaking in a scooter engine, as you have already discovered there are two schools of thought. Breaking in an engine's primary goal is to seat the rings and reduce blowby. Both of these increase power.
A secondary goal should be to control piston skirt and cylinder wear as it relates to high revving and thrust. Most people fail to consider that these engines revving @ say 7k rpm, the crank is traveling at twice that speed or 14k rpms. To put that into perspective; the crank & piston is cycling at the rate of 233 times PER SECOND!
If you ride it as I do, then you will quickly find that you need to push the engine's limits everyday. However if you do this you need high quality synthetic oil and something in the fuel to lubricate the top side of the piston (not the dome) as that area does not get enough lubrication to protect it. Failure to provide the additional lubricant will yield premature failure.
On the other point of view, you get rings that may never seat (seen that a lot on teardowns) and the engine has excessive blowby and of course lower power. Even in this the top side does not get enough lubricant, but most people don't want to listen to that.