[DonRotolo]

Bryant,
First, congratulations on wanting to push the envelope. Just some caution: This makes a great off-season project, where you can figure out exactly "how" to do it all. The 6 weeks of build season is a bad choice of time for learning all this: You have too much else going on at that time. Consider putting off implementation on a competition robot until next year. (It is a good path to failure and frustration, otherwise)

That being said:
1. Yes, you can use most any kind of sensor for feedback on pod position, including an analog absolute encoder. But the evaluation of that sensor may need to be done in the RoboRIO, and not directly in the Jaguar. Not a big issue.
2. Not really, they can all do it, and all very well. The ONLY advantage would be if someone knows a particular language better than any of the other languages. In your case, it appears LabView would be the logical choice.