This question has been asked a thousand times. There is always a chance that you will get banned, although the chance is slim. It's up to you if you want to risk it.
Bro, I got 99 strength on my main botting at giant spiders (F2P) 10-12 hours every day. 2-3 hours is nothing, but make sure you check on the bot often.
I personally think it helps to use quickchat worlds btw. People are less likley to try to see if your botting on them, imo. Which most bans are from player reports.
2-3 hours will not put your account at much risk. Make sure you're not wearing generic gear (Rune/Granite/D Med) as it is common among botters, makes you look guilty.