As Swiftie said, I believe a calculated grinding/quest profile would be the fastest, setting upon a set grinding path, and then doing the research to see if there are any quests on that particular, and if so does their average time required to complete (for a bot) outweigh straight grinding in that spot & it's risk/reward factor; killing 2 birds with 1 stone. I'd honestly stick to 'talk to turn in' quests & straight grindy quests (Kill 10 boars) to minimize the risk as Swiftie said and have the safety of mind to not have to constantly watch the bot.
I don't see why, even if it's not fully automated, that's by far good enough