Here is mine solution to bots in compete environment.
Force potential botters to be near PC and DO something that bots CANNOT DO - go through jumping puzzle iq / skill test.
When certain amount of reports acquired - game automatically put account wide debuff that block using of mounts,gliders,portals,tp to a friend, and disables player to go to wvw or pvp matches.This debuff can be removed if some specific or random jumping puzzle have been beaten (put bottle that cleanse this debuff into final chest).
There are multiple things that should be done :
1) Jumping puzzle.You need one that forces character go throw all checkpoints,coz botfarmers probably goona park alts at JP chests.Or create a unique JP inside Mists map,a puzzle that cannot be beaten by any AI - add alot of fake/instakill/disappearing/colored/floating/random moving platforms.
2)Fake reports - angry players,trolls or bots goona report a real humans just for troll/insult factor.To compensate - a reward can be added to JP chest (PVP/WvW potions? Unident-d gear?) or bonus buff for beating JP for next 2-3 matches(renewable).
(Kinda) Ultimate solution for PVP:
First:
Rework pvp maps and add some super small but smart JP/traps at spawning area.Like 3-4 randomly floating platforms,or something like Deepstone Fractal `s western tetris corridor.Thing that require 5-7 seconds of player attention,also a good punishment for feeding/being dead in match.There will be no point in botting character thats needs to be babysitted after every respawn.
Second:
Remove "ready/not ready" buttons(the one before map selection) and force every player to finish mini JP/trap before start of match - in Mists Map.Ones that cannot beat it are automatically considered bots,afk,crushed players and droped from queue(stackable).
After all checks complete - initiate pvp map etc.Boting in this variant still available - botmaster have to be near PC every match start.