TheRock,
I'll answer your second question first: The short answer is no. The long answer is that if you sign a NLI, and subsequently attend another NCAA school without obtaining a release from the first school, you may have to "sit" for a year before you can practice or compete.
Question 1: D2 & Juco. Yes you may sign early with a D2, and then go to NAIA or JUCO without any immediate impact. However it is possible that unless you get a release from the original school, that you may be required to sit for a year if you attend an NCAA school even after 2 years at a JUCO.
The fact that you "can" do something doesn't mean that you should. If you sign an NLI with a D2 without really intending to attend there, then you are taking scholarship $ from another player that perhaps REALLY does want to play at that school.
If there is that much doubt in your mind with regard to the suitability of the D2, it would probably be best NOT to sign right now. (In my opinion)
