Whoa dude, calm down... :)
First, getting the arm to stay where you leave it. Your guitar has an Edge III bridge which I'm not familiar with. On my guitars (Edge Pro) I have to replace the bushes (white plastic rings) on the arm frequently. The guy probably told you to drill a hole in the arm to make it a little wider at the end and make it stick - not something I would have suggested but hey. Does your trem arm have white plastic rings? the arm dropping is just the way they are with use.
Also, on my guitars I have to cut the ball-ends off the strings so I'm not certain. If I assume the ballends vanish into the trem block (like on a strat etc) it is possible that one has gotten stuck. Same suggestion as before - detune your guitar and see if one of the strings makes a big difference - might help you target the problem.
I'm off on a train soon, but can still get to the internet - PM me when you reply, I'll get an email and will know to check back in with you. Stay cool man - this is all part of the fun... honest... ;)