#1
I have heard and read from various lessons that, when using the "Picado" technique, you should hold your thumb on the 6th string.
Is this considered as anchoring and should I practice Picado without touching the 6th string?

Here is an example of this technique, in case anyone didn't understand, what I was on about
http://www.youtube.com/watch?v=m4Jj5Gqz9xQ
#3
there is nothing wrong with that, heck even with pick style i lightly anchor at times, but thats just the pinky and it moves around alot so its not total anchoring...however dont dare pinky anchor when trying to picado...for me it caused major crampage lol, but ya resting your thumb on the string above the one you are picking picado style is normal IMO, bassists do it too i think.