Yeah, I have those problems too. Rope tangled up in the drop zone. Not releasing the load quick enough, so you end up getting hit. Worst 1 I had was a newbie stopped the load dead and the butt came back and hit my hand whilst holding onto the trunk. Just a few choice words normally makes them remember.
Knots are an ongoing issue for some, there is only 3 they need to remember really. Figure 8, running Bowline, and Marline spike. But the new lad is getting there.