Yay, another fellow PvP enthusiast (seems like our number is quite growing lately 
).
In regards of PvP:
As it´s already been mentioned, the devs said that PvP won´t be a major focus of this game.
But nothing has been set in stone yet and I´m sure that if enough players are campaigning for PvP the devs will take a 2nd look at it.
In regards of floating trees:
The, already mentioned, world regeneration will take care of most of this issue but additional mechanics for this have already been discussed here.