what kind of work do you do?
have you had any hard hits during football or car accidents/whiplash?

Improving your posture is a simple thing to work on , that might help a bit.

The visible pulse beating is something to get checked out possibly a vascular type of doc. {Heavy, swelling, cold arms}

Improper form at the gym, or working to overdevelop the traps or other neck muscles can cause impingements by crowding the brachial plex area.

did you find out useful sticky thread yet - it's loaded with info - post # 1 is a crash course full of links.
http://neurotalk.psychcentral.com/thread84.html
dr & PT sticky-
http://neurotalk.psychcentral.com/thread135.html