The rules for the collar sound reasonable enough with those constraints. As for Lorag's search outside, there had been so many lycan tracks along that patch of ground during that time that picking out Harriet's would be nigh on impossible as long as she would retrace their steps. There wouldn't seem to be any more of her tracks branching from it in the local area, so Lorag could deduce that Harriet would indeed have taken that angle.

I don't think Kaleeth and Janius would be too far behind. It depends how long Kaleeth would have spent not talking.