I've botted countless hours with combat and I haven't had a problem with bans.
Combat isn't too much of a red flag as compared to agility, runecrafting, and other money makers.
Read the reviews before you use the bot, or as suggested above, use the LITE version if there is one.
I can't really give you a x/10 rating, but I've been botting on my main account right now everyday, sometimes up to 10 hours a day with different activities in between. If you want to bot on your main a lot, I highly recommend doing side activities because it'll keep them off of you a lot longer.
I'm monitoring it since I'm off work until next week but I feel comfortable enough that I can leave it by itself.
Yes it'll be disappointing if I lose the account, but it's a risk I'm taking.