it's never "100% safe" but you can be smart about it. Doing pvp and dungeons while not paying attention to the game at all is unsafe if you ask me, because players might notice you botting and report you for it. There is a pattern while botting and the character will not do the same motion as yourself and therefor it can be kinda easy for other players to notice and report you for using a bot.
I only use botting for leveling and some easy grinding when there aren't many people around and i never let the game out of my sight.
So here is my tips:
+ Keep track of your character (I use my second monitor)
+ Don't do Dungeons / heavy grinding / PVP around of other players. Because it's easy to notice a bot.
+ Do not use the bot 24/7. i'll never botting while i'm sleeping or at work etc.
+ If i notice my bot is questing around other players i stop the bot and doing that part of the quest on my own and then resume it when its safer.
If you do that i think it's pretty safe to use a bot.