Hey Roma,
I was just running imp catcher and the bot got stuck. It kept walking back and forth between the halfway across the bridge of the wizards tower and the draynor bank. This was on F2P.
Also, goblin diplomacy wouldn't work until I mixed the dye manually (it withdrew the goblin mail then the blue dye and just froze). This was also on F2P.
One other thing...I had run dragon slayer on F2P about a week ago and it got stuck multiple times. One time which was where it was "exiting melzars maze" and it just got stuck at the ladder. Another time it got stuck trying to click a ghost (to get a key) through a wall. There was at least one other time it got stuck that I do not remember.
Zoom on default, none of these had error messages. I guess the quester is mostly made for P2P with jewellery teleports?
I mean it works great on p2p, not sure if you're interested in fixing it for f2p but I thought I'd let you know.