I don't think I'm conflating anything, so much as speaking to interrelated problems. One of the huge issues with the present MI system, and Constructs, that was explicitly credited as the reason for removing one and massively overhauling the other, was that they allowed PCs to get easy access to abilities outside their class, or outside the PC skillset entirely. PPs as written add both back into the game.
I am of the opinion that you are failing to recognize the aesthetic constraints on these PPs. With magic items, any fighter could pick up dozens of Prisons, Banes, and Life spells. Similarly, casters could pick equip weapons that effectively gave multiple proficiencies and equip high armor.
Paragon paths don't create the same "buffet table" style of optimal delights. When they do offer skills outside of your standard skillset, those benefits are specifically limited in scope and often power. There simply isn't a paragon path that allows a fighter to get 20 Life spells per day. I haven't read them all, but I suspect, at best, they could get 1 (or maybe slightly more with restricted use).
As an example, I play a Scout. Looking at Duelist, even if I picked up all five levels of it, I would gain exactly 3 benefits outside my standard skillset. I would gain a 1/day bind, the ability to swing some modestly useful carriers against a single target (best are slow, bind, and weakness) at the cost of a crit/ba, and the ability to swing the repel carrier against almost anyone for 10 minutes at the cost of a terminate (limited by the fact that my damage against those targets would be base weapon damage). All other features grant benefits that are within the skillset of a Scout (though admittedly the final feature is similar to having bought Hearty about 15 - 20 times, in regards to a specific target).
If I wanted those abilities (or something close), with magic items, I would take a 1/day confine (not bind) and probably way more than one. Similarly, I would choose to swing Shun as a carrier (or simply get multiple daily use shun items) well before the much more limited Repel.
I don't have those options, though. I take what the paragon path gives me and smile (or frown... doesn't really matter).
It is possible that some paragon paths are badly balanced. If that is the case, then the specifics of that path need to be tinkered with. But mechanically speaking, offering benefits beyond the scope of standard skills, that are limited both thematically and in power level, is actually one of the BETTER ways to ensure that a game remains both balanced and interesting.
-MS