Specifically, regarding the third issue (adjusting switches), here's a good link:

http://www.pinrepair.com/em/index2.htm#clean
[Section 2f. Before Turning the Game On: Adjusting & Cleaning (Filing) Switch Contacts]

Do you have a schematic and manual? IPDB has the schematic, but you should also purchase a paper copy (details in the popup window on IPDB). They would be a great help in finding (and/or confirming) the home for that broken red-ish wire. Look closely at all the switch tabs in the area, see if you can find where it broke off from.

The two yellow wires look like they broke off the switch tab and were reconnected using that short green jumper - definitely functional but not the neatest fix. Maybe use some electrical tape to cover the connection until you get around to cleaning it up.

http://www.pinrepair.com/em/index2.htm#steps

Clay recommends testing the tension with the wipers installed on the stepper:

[Quote from his site]

"14: Check the finger tension on the rivets. Gently pull a finger back from the rivet, and let it snap back to position. It should snap back firmly, but without too much tension. Fingers that are too tight against their rivets will make advancing or resetting a stepper unit too difficult. If a finger has too little pressure, there won't be good electrical contact between the finger and the rivet. If a finger needs additional contact pressure, remove the finger plate and gently bend the desired finger. If it has too much tension, just bend the finger back slightly (without removing anything). "