Storm Raven said:And? You aren't making any kind of argument here other than to say that everything is temporary except (apparently) for skill points and feats. That makes no sense.
Skills and feats are special abilities.
If you lose your Int bonus due to a poison, you do not lose the skill ranks that you already have no matter how many Int points you lose. You might lose from your total on a given skill, but you do not lose the skill ranks.
You do not lose your feats, but you may lose your abililty to use your feats.
Storm Raven said:Feats are not unique either. You aren't making a coherent argument here.
Let's use the word "individualized" as opposed to unique.
Everybody gets hit points.
Everybody gets BAB.
Everybody does not get the Open Locks skill or the Craft Wondrous Items feat.
Unlike many other aspects of the game, we are not talking about what you get as bonuses due to ability scores. We are talking about what you qualify to do because you have a given ability score.
Using the Similar Rule rule to discuss the bonuses acquired by the item is comparing apples and oranges. Using the Similar Rule rule to discuss your qualifications is closer to comparing apples and apples.
This is no different than level or spells castable as prerequisites. Would you allow a magical item that boosts your level or adds higher level spells which you cannot normally cast as a prerequisite for a feat or for a prestige class?
For example, a Minor Ring of Spell Storing:
Spell Storing, Minor: A minor ring of spell storing contains up to three levels of spells that the wearer can cast.
If you have an x level arcane spell in this Ring and are wearing it, do you qualify as an "can cast arcane spells of level x" for feats and prestige classes?
If not, why would you do the same for ability score enhancement items?