Actually one casino I know in Washington called Tulalip Casino, I believe there is a rule that states that dealers can play but cannot check-raise.

NV doesn't allow shills to checkraise. Props, however, can do so.

I played again last night and by pure chance, the first dealer was the Hit and Run Dealer in the OP followed by Female Dealer in the OP.
I am pleased to report that neither one of them had a slightest interest in anyone's mucked cards, even on the big hands.

EDIT:
I can't remember exactly the action other than it was Heads Up all the way and she never missed a chance to raise/re-raise.
I was the one who had to stop raising on all streets.

In the private games I play, 2 dealers might rotate downs at 1 table for 8 hours. They can get decent reads on every regular, and often do have good insight on a player's tendencies. For example, if I'm railing while waiting for a seat and chatting with an off-duty dealer, I'll be impressed by his hand readin skills.

That being said, pretty much without exception every dealer that I've played with regularly has lost a huge edge in their game compared to before they became dealers, 'cept against the most basic ABC players. I'm still trying to figure out why, think alot of it has to do with their tip money making them looser because they might feel they're playing with house money.

In the OP's situation, if she has such a big read on him she pretty much is telling him how to switch it up.