1. Is it possible to go from completely off a recruit's list to signing him immediately at the start of signings if said player was already considering another program going into that cycle (honest question, I'm not sure if it is)? If two or more programs are being considered by a player though, in my eyes that's already a declaration of intent and those players need to recognize the chance that a big push might be made.
2. I try to not battle in conference, but if we both land on the same recruit at the same time, it's game on. If I have to move onto a recruit because I got knocked off my first choice or if I missed the early cycles (because they start at noon my time) and I think I have a strategic advantage, I'll do it. Generally though there's not a player of high enough quality (D2 and D3) where the good of battling for the player overcomes the weakness caused by forcing 2 members of your conference (you and the other guy) to expend their resources to get the player. Very rarely do I see players that I don't think I can find a comparable counterpart for that I won't have to battle for if I look hard enough or show some patience for drops. That said though, my goal is to beat my conference mates in the season and postseason, so if I need to, I see nothing wrong with trying to beat them in the signing season as well.
3. I don't think there's an unethical TIME to grab a recruit (unless you hack the server and sign them before anyone else has a crack...). There are unethical WAYS to get a recruit (colluding, using information you didn't pay for with that team, etc.), but as far as the when question, any time during signings is a "good" time to grab a kid if you're able to.