1: Yes...or Female x Poly adapter and a male threaded valve...or a valve with male poly barb...
2: I will get shot for this, but during repairs I have been known to go over 10' with poly. When I perform a new installation I keep it to 1-2 feet or max of 5 feet...not because of any design issues, just because I can get the lateral lines within 5 feet usually. I don't think it hurts to have 10 feet of poly....just me.
3: Yes
Sprinkler Solutions, Inc.
Arizona and Colorado
www.sprinklersolutions.net