Best to bot certain types of bots while watching and some can leave without watching for example you can leave fletching and herblore bot running at ge on world 2 and cooking bot in rouges den on world 2 others skills id watch while bot runs. other thoughts make sure the bot is human like enough...
Blast Furnace bot would be really great money 500k to Mill / hour.
Small location mini game so mapping and programming it would be easy.
Its probably the highest profit per hr that has one of the lowest requirements for.