Frequently Unkown Rules (Pathfinder)

First, this is not a lazy post (really). The reason is that I couldn't let pass this amazing discussion at the Paizo message boards, where Pathfinder players started a compilation of "Frequently Unknown Rules": usually about minutiae that were changed from the original 3.5 SRD, but also many other rules that just were passed by many groups.

I remember that when the 3.5 Revision came out I read (from cover to cover) all the three core books again; however I didn’t found the same enthusiasm (and time) to repeat the process with Pathfinder.

The post is big, so if you don’t have time, check Howie23’s excellent synopsis.

Some “discoveries” resulted from reading the post (again, at least for me):

1. Detect Evil not only detects evil but also malign intentions, without regard for the target's true alignment.  All other Detect (alignment) spells work likewise. 
2. Fighters can retrain bonus feats granted by their class.

Very interesting stuff.

Now, I summon the The Joeskythedungeonbrawler Protocol to save this post from laziness: an old house tule that I use since the 3.0 Edition is to double the Ability Score bonuses when rolling “pure” Ability Checks. It may seem silly, but D&D usually kept the same base DCs for both Ability and Skill Checks, which I thought wasn’t  fair because Skills always had much higher bonuses. However, I admit that I’m going to read Pathfinder again to see if this house rule still makes sense.