Home game rules for showing cards

[MathBabe]

I haven't been at the monthly "home" (really an office boardroom) game I used to go to for a while. Mr. MathBabe went last night, though, and there was apparently quite some discussion about when to show cards. I thought it was pretty straightforward - you're called, you show - but I guess some strange scenarios can come up, and there was one player in particular who felt they were being asked to show their cards more often than they needed to.

Here are the rules I saw proposed today, by the organizer, who is by no means a poker expert:

1) "A player must show all cards in the hand face-up on the table to win any part of the pot."

2) "If everyone checks (or is all-in) on the final betting round, the player who acted first is the first to show the hand. If there is wagering on the final betting round, the last player to take aggressive action by a bet or raise is the first to show the hand."

3) "Any player who has been dealt in may request to see any hand that is eligible to participate in the showdown, even if the opponent's hand or the winning hand has been mucked. However, this is a privilege that may be revoked if abused."

1 is obvious, and 2 seems to cover almost anything else. But what is up with 3? If I was dealt in and folded early, I can request to see the cards of someone in the showdown who didn't contest the pot?

Does anyone else play home games that work this way? How would you define "abusing the privilege"?

MathBabe