A2: If looking to have the best shot of competing for a NT berth relatively quickly (once you actually arrive at DI), you might first develop a solid D2 program (of hopefully 4 years or more of solid NT runs). Then you can move to a C-ish prestige program. You'll be able to compete for better talent right away. Even with that, you'll need to do a good job of identifying players not highly coveted by the top prestige programs.
But in short, the lower prestige you have in DI, the more CAREFUL and less GREEDY you need to be in order to maximize the chance of success and minimize the chance of disaster.
At a D- or D school, first of all, you won't even be able to talk to top players, and most mid-line players will be backups. And backups at DI are pretty much off limits. This is very different from D2, when successful programs live exclusively off backups.
Finally, since you've just started your career, my advise is to learn the game a few years at D3, then at D2, then make the move to DI. There is no race to win currently, with all worlds well established. If you want to get to a good Big 6 program one day, there is plenty of time. Learn the game, ask questions of vets, and move up with care. Good luck.
-jskenner