You cannot be banned for using hacks as long as no one uses the Violation report on the GW2 website with video evidence. If they report you for botting in-game, you will be banned after numerous reports. If the later situation happens, send an appeal to GW2 support with the usual yada-yada about how players are raging for no reason and reporting you and after about a day and a half you will get your account back. It's happened to me 4 times now already, and each time, GM Lloyd responds to my appeal says how he sorry that the game mistakenly took me for a bot. Have fun hacking =)