yes
Navy SEAL snipers are fully trained ground soldiers who just specialize in sniping.
Yes
Not all Navy Seal missions will have snipers, but at least seven missions will have snipers that they are trained for.
that is part of SEAL's operations...............
The best.
SEAL sniping is a specialty meaning they don't do it as a full time job. Marine snipers do it 24/7 so i'd go with the corps.
Yes, NAVY Seal snipers can serve as ground soldiers on missions. This, however, would be up to their commanding officers. It would also depend on the military objective, goal, or excursion at hand.
as a cue to tell other snipers to fire their weapons
When you see the snipers lay on your belly and crawl
probably marine force recon or scout snipers
None VERY VERY few, because Navy SEAL snipers are always hidden. Even when they move, they are either in gillie suites or they move when no one is around or by the shadows, Navy SEAL snipers never get compromised unless they miss, which is almost never.
the seal snipers used a .50 caliber Beretta to kill the pirates