1. I can't remember - are all recruits "available" at B? (Available meaning open to effort - that doesn't mean you're gonna have a chance in hell to sign certain ones - but mostly because someone else will take them...)
2. This is the wrong way to think about recruiting IMO. Both parts of question.
a. nationally: You should always be recruiting where you can either gain an advantage, or neutralize the advantages of your opponent. Assume every target is attractive to others (if they aren't why the hell would you want them in the first place). It is important to try to construct your recruiting plan such that you are able to minimize threats and defend against attacks as much as possible. If you can do so nationally or at a distance for whatever reason, great.
b. battling: Recruiting the highest level players you can is a big part of one popular way to "succeed" in HD. It is tough at any level, even A++++ (ask gillispie how things went at KU in Tark this year

) Learning what schools you can battle and when is a big thing - more than I could try to express in a response here, and more than I'd have time for individually personally, but I recommend seeking a tutor familiar with high D1 recruiting for some personal advice if possible...avoiding battles is generally best (GENERALLY) and recognizing which battles are win-able and which aren't is paramount to success...
3. I don't understand this question.
I am not sure I actually gave you any useful information, and perhaps you've received some sitemails in response to this already, but it looked awful lonely so I wanted to say
something at least...