Re: "But my players say they're official rules..."
It's a good idea to establish a standard rule beforehand on whether products will automatically be included. For example, I use the following rule:
1) CRB is included entirely.
2) APG classes, feats, equipment, spells, maneuvers are included. Traits may be included or more campaign-specific traits may be homebrewed. Hero points will probably be used.
3) UComb classes, feats, equipment, spells are included. Wacky stuff like performance combat and optional rules like armor as DR is ignored because I can't be bothered to read it.
4) UM classes, feats, equipment, spells are included. Nothing else from UM is included.
5) UCamp retraining rules will probably be included.
6) Magic items from beyond the CRB will not be included by default. As a GM I will probably occasionally drop them as loot.
7) Anything else from Paizo, high-quality 3PP or even homebrew may be included if a player wants it, but subject to the following:
- I reserve the right to just say No, just because.
- I reserve the right to revoke permission because it doesn't work well. The PC will have to trade it in for something else.
- It should fit the campaign world.
- It doesn't unbalance the party, inernally or externally.
- It doesn't steal another PC's niche.
- The rules are easy enough to apply.
- The player has a printed reference available for himself, and one for me. Photocopies are fine. Looking it up online isn't.
In addition, I want sufficient time to study the thing. I don't want to be taken by surprise by a power that I've never heard of before or that I don't undertand. I comprehend the core game, I refuse to give players options from outside the core game that I don't understand sufficiently.