When Play with Escape From Tall Oaks:
Yes, much like regular players, you must be holding a weapon in order to fight or attack.
If Anonymous is drawn out by noise or the Slasher meter, but has no weapon, then they cannot attack. This could be an opportune moment for one of the players to fight back and hurt Anonymous.
If Anonymous is drawn out by noise or the Slasher meter and both parties do not have weapons, no brawl occurs.
Yes. Anonymous plays just like a regular player, only their goal is to eliminate all players and stop their progress during the game.