1) I believe (my guess) that a pawn will be able to continue any game (including pond) until it is over - just will not be able to start any new games.
2) Yes, this is getting boaring quickly. I believe after the new years (which Fencer is doing some archiving and other things like that) - he will hopefully look into creating some more pond games with the limit of 25-30 players - which should speed things up and make the game a lot more fun. (Current game will get fun - but it will take awhile before we get rid of enough players before it really starts to get interesting.)