1. Would need more detail to help with this one. Could be a number of things. Which digit is sticking? Once you figure that out, check the relay that controls that digit and see if it is staying energized. If so, that relay needs adjusting probably.
2. I haven't done a flipper rebuild yet, but this may be needed.
3. Use Novus 1 for all the plastics. Use Novus 2 for the playfield. Use a pure carnauba wax after the playfield is completely cleaned.
4. should be a number of sites that sell rubber kits. I just googled my machine and found plenty of options.
5. Do this before cleaning the playfield. To best clean the playfield, you want to completely remove everything. Take tons of pics so you know how to put it back together.
6. This can be done at anytime. Cabinet or playfield or both? If it is playfield, here is a thread that can help:
7. Pinballlife.com has all kinds of parts (rubbers, balls, lights, etc)
To start, order all the parts and supplies you need. Once those arrive, take apart the whole playfield and clean it and wax it. Then replace all the playfield parts with your new rubbers and what not.
Enjoy. I just completed my first EM repair, and it was a lot of fun. Take your time, and take lots of pictures for anything you take apart. Also use ziplock bags for parts that you take off and keep things separate.
I hope this helps.