In my most humble of opinions...
1. Bone or if do a crapload of bending, graph-tech works well (keep in mind you may have to trim this down a bit and make it fit correctly)
2. 6 if you're super **** about intonation, 3 otherwise (worked for NUMEROUS musicians)
3.Wilkinson and Fender make decent parts for this, the trick is getting the correct measurements, or being ok with drilling holes in the body to mount the bridge. most of them are steel or brass. I like brass saddles on a tele, but that's just personal preference. Also, make sure you get a top load bridge unless you have a string through. Sounds obvious, but happens frequently.
4. Yes - Check out Guitar Fetish if you're budget conscious, otherwise there are numerous tele replacements out there that will probably provide more of what you're looking for
5. If they're working fine, leave 'em
6. Nope
7. The stock electronics are the cheapest possible mass produced stuff they can get. It's always a good idea to make sure you have quality electronics (like from CTS) in there.
You may also check out tdpri.com for more info about modding Teles in particular
Hope this helps