1. I always saw it as a sign of respect. We also kiss the Priest's (and Bishop's) hand if we receive a blessing from him. All you have to do is ask him for one, and he will bless you. You should cup your hands in front of you while he blesses you (I would suggest with your head looking down), and then he'll put his hand in your cupped hands. Then, you kiss it.
All you have to do is go up to him when he isn't extraordinarily busy and say "Father, may I have your blessing?"
2. Georges Florovsky had a problem, how can I answer it?
The safest approach is not to "define" the Church so much as "describe" it. The Church is essentially the communion of the saints, having the same dogmatic beliefs, central traditions, and having valid apostolic succession. I think Ignatius said something akin to the RC view, except he applied it to all bishops. A valid Bishop, Priests, other clergy, and lay people, on the local level, participating in valid sacraments make up the Church. You aren't more of a Church by being in communion or out of communion with this or that Bishop. None of this is a definition, it's just an admittedly brief description.
3. One question that might be asked about is proper apostolic succession. We see very clearly, very early (96AD) the firm belief that Christ purposely appointed people who were in turn suppose to appoint (or more correctly, anoint) people. And why? Because, as Clement of Rome says, it was known that divisions would arise. Now, apostolic succession doesn't guarantee orthodoxy, but it does play a large part in a system that can be used to get the local Church back on track if it goes off course. What happens once the apostolic succession aspect is forsaken (ie. forsaken in content, even if the formality is continued, as in some Protestant Churches)? All of a sudden numerous schisms start, and these spawn schisms, and those schisms.... well, you get the idea. Whta's my point? There were certainly schisms in the early Church, but as long as everyone agreed with apostolic succession there existed a system of bringing everyone back together. Some of these schisms remain, but even now the system still offers the best chance for communion. After all, which would be easier, bringing the non-Chalcedonian Churches and the Orthodox Churches into communion, or trying to get, let's say, the various Wesleyan groups into one unified Church? I submit that God, knowing that there would be divisions, gave us a system that would at least give us a way to come back into communion (and it worked many times in bringing local churches back into communion with each other). Actually, I don't think I answered your question at all, sorry :-
PS. I can give lots of early quotes on apostolic succession if you'd like.