Hallo tjb and welcome to the forum. I'm sure other members will chip in with good answers to your questions, but here's my quick 10-penn'orth for the moment:
The balances may be rocking - and I take it you mean up and down as opposed to the normal swing - for a variety of reasons such as cracked, misplaced or missing jewel, damaged pivot, wrongly seated plates, etc.
Watch case restoration is very expensive. If the cases are not physically damaged, just brassed or pitted, then you could try some cleaning, polishing and buffing yourself. If the watches were bought as initial trial and error watches, then that might be a good exercise.
It's always possible to relume hands yourself - Mark has a very useful video showing his technique (which I've followed successfully). Dials are a different matter and you have to take care not to make matters worse. Full dial restoration by a professional firm is something in the order of £100 - plus or minus.
As far as crystals are concerned, you need to consider profile and material. Here's my web page on crystals, just for starters:
http://www.willswatchpages.com/watch-glasses-and-crystals.html
Cheers,
Will