The itchy thing is normal. You will see less and less of it as time goes by. The unenthusiastic thing happens too with some dogs at first. When you first start to layer prong pressure they're like dude this sucks and are confused. To a certain degree you can make it better by teaching them to give in easily to pressure by marking it and rewarding when they give in like in those Michael Ellis YouTube videos.
You might also try bringing them up with your own enthusiasm.
My personal favorite though is to use retrieve play. Prey activity blows stress off a dog really quickly. Ask for 2-3 behaviors and when you get them mark and reward with retrieves. So for example teaching sits. Say sit, quickly give upward leash pressure, dog sits, say free excitedly while moving the dog out of the position so you can reset. Repeat sit command and start all over one more time. At the end of the third sit instead of saying free mark with a yes, then pull the retrieve toy out of a pocket throw it and drop the leash and let the pup have a retrieve or two.
If your dog doesn't know retrieves yet I'd work on that first and build value for it so that you could use it as a tool, as well as just a game you can play with the dog in general.