1: You can bid for every player who is on same server with you but he can't be bigger then 5* for you.
2: You won't lose anything if he will reject your offer but till he will accept or no your offer you won't be able to use that tokens/moneys on something else, they will be like "blocked".
3. Not sure how is going, they should explain better this system but I think there appere all players who got a negotion offer.