Let's say I wanted to make a Shadowdancer. Other qualifications aside, I'd like to ask about having ranks in Stealth.
"To qualify to become a shadowdancer, a character must fulfill all the following criteria.
Skills: Stealth 5 ranks, Perform (dance) 2 ranks."
Considering a core character with no special mechanics or tricks, what does it mean: a character must fulfill all the criteria?
Can I take Shadowdancer as my 5th character level with a 5th rank in Stealth thereby fulfilling the criteria? Or do I have to wait to take Shadowdancer as my 6th character level?
You must fulfill all the prerequisites for a Prestige Class before you take it. In this case, you would have 5 levels of base classes, then your 6th level could be Shadowdancer.
Specifically, because choosing what class you are going to level in occurs before gaining the benefits of your new level.
Are you guys arguing that one could not use their 5th or 7th level feats to qualify for a PC at that level?
There's no argument, you can't. The book is quite clear on it.
When adding new levels of an existing class or adding levels of a new class (see Multiclassing, below), make sure to take the following steps in order. First, select your new class level. You must be able to qualify for this level before any of the following adjustments are made. Second, apply any ability score increases due to gaining a level. Third, integrate all of the level's class abilities and then roll for additional hit points. Finally, add new skills and feats.