The only reason I'd give it longer breaks around 6 hours is that's when the forced log happens anyway, and an immediate/automatic login back to another 6 hours of continuous play might seem suspect. So i'd take advantage of that and use it as a natural break time and then continue. On this same...
I wouldnt say manually, I would leave it to do its own thing for hours on end, but for the most part I was on the computer just on my main or doing other things, so I'd glance at it every once in a while to make sure it's not stuck or anything. Any time I did leave it going while I left it...
Honestly I rarely used breaks. I mostly had it running about the same as what i'd run my account. So if I get off, I'd turn the bot off. The exception is going to work, I'd give minimum 2 hr run time and maybe 15 minute break. Max 6 hours of run time at once, at least an hour break if i reached...