Nice post Giorgio,
You are at least heading in the right direction! A lot of people just keep going to the slope making it down the hill anyway they can. Its nice to see someone who has the self motiviation to try and learn.
I will try to answer as best as possible your questions, although I am just an intermediate skier and just started PMTS myself. Unlike you though, I was fortunate enough to have 2 private lessons with an instructor earlier this year. (please excuse my generalization between PSIA and PMTS instruction..these just come from my experience in private lessons)
1. It is a huge advantage to pick up "Anyone Can Be an Expert Skier 1 and 2" in addition to the book you have. It is also a huge benefit to be well versed in these books prior to going to a PMTS instructor or camp (at in my opinion). This is because I already had a base knowledge of what the instructor was trying to teach. I read the books before my lessons, but never had time to try anything out, but this was even helpful because I understood the principles behind the method and the instructor didnt have to waste valuable time explaining everything..he only explained any misunderstandings I had. I agree, you can probably self teach a lot of stuff, but like anything an expert will be able to see if there are any inefficiencies and help you correct (probably at a lot faster pace). I think of going to camps or private instruction as like a steriod shot for muscle regrowth. They give you a great deal of knowledge and things to practice on your own, then you go work on these. Then when feel that you've gotten to a proficient level you go back for another "shot".
2. Whoa...if you read a lot about PMTS vs PSIA (which I have) this is huge discussion/debate...lol...I hope it doesnt get to that here because most of that discussion is probably over my head. From my personal experience, the biggest advantage of PMTS is that when you ask "why or how does doing this make my skiing better" (at least my instructor) could explain in exactly why it was better mechanically and kinetically. This is probably because he had a PhD in Biomechanics! If you really want to learn more you should read up more on the PMTS forums because they have a lot more room to talk about the difference between PSIA and PMTS.
The other huge factor for me was the stress that PMTS has on proper equipment. After going through about 13 private lessons with the wrong boots, it only took my PMTS instructor 1 excercise on the first day to figure out that I was out of alignment. I already knew my boots were probably too big, but it never seemed to bother my PSIA instructors, it definitely disturbed my PMTS instructor. The next day I took a day off from skiing at Vail, to drive to Harald Harb's shop and got fitted for new boots and aligned. My old boots ended up being 2 whole sizes to big! and I had to get a 2.5 and 3 degree "wedge" on the soles of my boots. I wasnt sure if I was going to be able to tell the difference...it makes a huge difference! Think of it this way: with improper equipment you can ski and probably learn to ski, but there will be a point wihere it will restrict your learning ability. Why waste time trying to learn with improper equipment, why not get the proper equipment first then start learning, this will maximize your learning potential with no restrictions (then the only restriction is yourself). the PMTS camps start off the first thing with alignment sessions for this reason. It is never too early to get proper equipment.
3. Duh!! you hit the nail on the head. Even after just 2 lessons I enjoyed PMTS much more then PSIA. I kept telling my instructor I wanted to ski around to all of the other people with "blue jackets" (All vail instructors where blue jackets) that there is something way better then what they were learning!
The only thing I can think of is that PSIA was here first and is "developed" and people are ingrained (spelling?) into that school of thought. So when some one, no matter their background, comes along and says that they found something better. How quickly do you think people (who have been training for 10+ years) want to change? I would equate this to Copernicus when he told everyone that earth was not the center of the solar system. This is kind of what happened to PMTS, which is unfortunate. But if you look at the people involved in PMTS you will see most of them are PSIA certified and some of them were very high in the PSIA organization...I thnk this also lends to the credibility of the system.
4. I am a firm believer that helmets are a MUST. Although I just bought a helmet this year for the first time because I am a convert. Unfortunately this disucssion is the exact same as helmets for motorcycles... people want to rebel and dont want other people forcing them to wear helmets..its ok, natural selection will take care of this discussion over time. The reason I changed beliefs is because even if you are an expert skier, which I definitely am not, you will hit things seen and unseen. Besides the things you have control over, you do not have control over everyone else on the slopes. Im more afraid of the lack of skiing ability of others than my lack of skilll. This is because I know that I wont do terrrain that is way beyond my ability. I know people will argue some statistic that helmets would have only prevented 1% or some low percent of all fatalities associated with skiing...but honestly, is it worth taking that 1%...to be honest I can't say Im scared of dying Im more scared of ending up a vegetable and living the rest of my life, cuz that would really suck!
If you want a great helmet (kind of expensive, but way cheaper than brain sugery!) the giro 10 is awesome. Tons of vents, it has an adjustable band in it to make a good fit. You no longer have to have just the right shape to fit into it., and its so light I couldnt even tell I had it on! Plus, you dont have to worry about what type of hat your going to wear. It even has removable ear flaps to keep you warm