>>/12411/
> I'm FINALLY BACK!
Woo!
> Her detecting something off is completely correct even if she is starting run with it. 
This can be so tricky - intuition can be very good at telling that something's 'off', but then deducing the reason or cause for that 'offness' can get way into the weeds and overcomplicated, as Pinkie finds out. 
> The most I laughed during this episode was when Rainbow Dash casually said, “Hey Pinkie” when Pinkie Pie was in the hay bale disguise, no doubt used to seeing her in such a get up from their mutual pranking.
The casualness of the remark, I agree, comes from their mutual pranking activities - however, another thing I find amusing about this moment is that Pinkie, by wearing a disguise like that, announces to everyone that it's her since she's the only pony in town who would disguise herself like that! Real pony disguises would either be the province of Unicorn magic, or painting over cutie marks and perhaps gluing cosmetic horns onto the forehead.
 >>/12412/
> over implying any in universe lee creepy pasta mental illness.
it's also her cutie mark to focus on friendships and parties, part of which I imagine is having a close friend group. it is a rather sudden onset of her purpose going unfulfilled leading to delusional behaviour, true, but then, Pinkie IS unusual. 
> Albeit, the theory of when a pony cannot fulfill their cutie mark causing severe mental distress is still one that has appeal to me. 
It's clearly something ponies are not at all used to, and the same goes for not having their social needs met in general. I think it makes pony villains particularly interesting in the show, since they're both equals for the abilities of our main cast and are inherently interesting in terms of exploring how villains can emerge even from a utopian society like Equestria.