I have botted my main using a mixed bot that grinded and bg botted.
0 warnings, 0 bans ..
Exception that proves the rule, grinding is incredibly more risky as it is much easier to spot by other players and a GM seeing level 85 with no quests done but lots of npc kills will be very keen to see what else you do.
There really is no reason to grind either these days with kick's questing profiles and other methods of gaining xp, especially as they offer safety over pure grinding and much better xp/hr.