Whatever bozo wrote the step by step guide made it seem way more complicated than it has to be. Ian paraphrased everything you really need to know about idle jets. Most phbgs come with really rich idle jets and its usually best to downjet yr idle.
The symptoms you are describing have nothing really to do with idle circuits though. You are discribing either, a sticky throttle cable (common on pivoting moby engines) or the fact that when you are in your powerband you are consuming maximum gas, and when you suddenly cut your throttle you dangerously cut out your cooling 2stroke mix for a second in a high revving situation. Most seizes happen around this point if the bike is running hot. On a phbg/ and in a performance engine setup its a great habit to open up your choke circuit slightly when deaccelerating from a hot run to compensate for drastic fuel starving. Especially if you are jetted leaner on your mixture for performance Your problem could also be reed related.
Also 106 is generally way too rich of a mainjet for 70cc/19phbg setups. Generally, mid 80's is correct. That could be a compensation for airleaks. Though I'm not an expert on av10 jetting senarios.