For the first play, it's hard to know what's going on there. But there's no scenario on HS rules where you'd enforce from the previous spot for a foul downfield on a running play.
The second play sounds about right. HS rules still have the 5 yard FM, and it would be enforced from the spot/end of the run (sounds like those were the same). When that spot is more than 5 yards behind the LOS, you'll have a net loss on the play.