I'm attempting to create url like sub2.sub1.subdomain.domain.com. I'm likely to make use of this to show different content.

my questions are...

1) Can you really create such multi level sub domain names? - is in line with the webhost?
2) Is not sub2.sub1.subdomain another subdomain as opposed to a sub domain of sub1?
3) Will many of these subdomains get their own doc roots?
4) The way I handle customers coming with and without world wide web.

Every other potential problems that might arise?

EDIT:- So how exactly does this modify the behavior of snacks? Can One access a cookie set on subdomain.domain.com on sub1.subdomain.domain.com or sub2.sub1.subdomain.domain.com