Agree that the equipment will change his running. No doubt.
When looking at him running in open play remember that he is doing that with no blockers. You cannot block in the NRL.
As you say some of those tackle are arm tackles but not all of the NRL is like that. This is what defence is...
Hayne has a background in sprinting. Sure he has trained for NRL, but sprinting has been his basis. There is every chance that he would have been an Olympic sprinter if football didn't come along for him.
I am an Aussie and fan of the NFL and the NRL where Hayne currently plays (or at least did until a few days ago. I think you are on the money saying that the mindset will be the big change for Hayne. The two games are very different. He is going into this knowing that he has a lot to learn...