Is there a place in the NF rulebook that mandates an ejection for the second UC? For the second PF? I heard a conversation with two officials in which the ref called a PF instead of roughing, so the player was ejected on his second PF. I am also aware that we should eject after the second UC. Is this state by state, association by association, or NF wide?

Yes . Unsportsmanlike fouls for players are covered in NF rule 9-5, for non-players in 9-8. Check the penalty section in both. It in part says "Any single flagrant foul is disqualification. A second unsportsmanlike foul with a 15-yard penalty result in disqualification"

I don't think I actually answered your questions in my first response so here I go again.

In your post you ask
“Is there a place in the NF rulebook that mandates an ejection for the second UC? “
Yes there is and I’ve provided the reference.

Then you ask
“For the second PF?”
There’s no disqualification penalty for multipal personal fouls. But there is a provision that allows disqualification for any flagrant foul.

Then you go on to say
“I heard a conversation with two officials in which the ref called a PF instead of roughing, so the player was ejected on his second PF”
On this point I’m wondering if you might have miss-heard what was actually was said. I believe roughing is a personal foul. The only way I can see disqualifying a player for roughing is if you determine the foul to be flagrant.

Now... to address your last question....
“I am also aware that we should eject after the second UC. Is this state by state, association by association, or NF wide?
NF... WIDE BABY! (Again look in the penalty section of NF 9-4, 9-5, 9-8)