What skill or roll does one use when a character wants to guess the abilities of another player?
Specific situation 1: One of our players was in a fighting pit with 3 NPC's. Last man standing would get the prize money. One of the things one would do in such a situation is guess which opponent would be the biggest threat. Initially he had only the appearance of the NPC's to go by, but after a few moments standing back and watching them an experienced fighter should be able to make a reasonable guess.
Specific situation 2: My character (a rogue) sees a group of NPC's observing and trying to break into a building. Since we had to be in that building and therefore possible also had to deal with this group, we wanted to know how experienced that other group was.
What rolls/skills would one use for that? We couldn't find anything in the core rulebooks. I would expect that the skills (as a fighter/as a rogue) are involved. Are there any rules for this?
How would one handle the situation where the NPC actively tries to mislead the PC? For example, a fighter pretending to be worse than he actually is.
This would probably involve two rolls: one to detect the Bluff and one to detect the ability of the NPC as in the previous question. Here I would also expect the skills of the PC to be involved in the roll (an experienced fighter will easier see though the bluff of another fighter).
I guess that in the case of a fight one could use the rules for Feint (Bluff opposed by Sense Motive with the Base Attack added to the Sense Motive Roll). But I am curious if there are specific rules for this and also rules for other skills.
I am looking for official rules. Preferable ones which have been used and found working. Making up a home brew rule is probably not that difficult (ranks in skill involved (base attack for combat) with Wisdom modifier would probably do).