I Don't Know If This Goes With Any Of The Reasons You Gave But I Also Think All Of Them Have A Problem

I don't know if this goes with any of the reasons you gave but I also think all of them have a problem with asking for help

The main six all have autism,and heres my breakdown as to why I think that:

Fluttershy has pathological demand avoidance.

Favouring people- some autistic people can develop an extreme and borderline unhealthy attachment to those we cherish most,or look up to most.

This can make us overly dependent,make us overly emotional and clingy. We can react extremely negatively to being "cut off" from interactions with our favorite person,and that usually causes self destructive episodes or cause us to be destructive to others.

Rainbow dash,pinkie pie and twilight sparkle have developed "favorite people"

They have gone to great lengths to mimic them,spend time with them or to appease them,to live up to their expectations.

Anxiety- autistic people are more prone to anxiety due to the overwhelming stress and trauma of inhabiting a world that is hostile to those with disabilities. We are also more likely to develop anxiety due to social situations where we misunderstand social interactions,or social expectations.

Stimming- pretty much all of the main six exhibit stimming behaviors

Special interests- the main six have a rich array of obsessive and passionate behaviors/interests.

Preferring to be around other species,rather than their own kind- fluttershy much prefers the company of her animals,she seems to spend most of the time around them because she understands them and their needs and body language better. She enjoys caring for them,kept away from the stressful demands of other ponies.

Shyness or extremely extroverted- all of the ponies exhibit these two behaviors in their own varying degrees

Creativity,spontaneous bursts of creativity but difficulty with mainting the level of skills required to complete demanding tasks- some autistics struggle with creative projects because we thought we had the skill sets required to finish the projects in mind,but we currently do not at the moment.

This can cause us extreme stress and subsequently meltdowns,burnouts or shutdown. The main six have had experiences where they "bit off more than they could chew" so to speak, and experience distressed and a sense of shame,feeling like their best wasn't good enough,so why bother trying at all?

Rarity and rainbow dash and even twilight especially demand perfection of themselves,going to great lengths to prove their worth and show off. Ultimately causing too much stress.

Being confused by sarcasm,figures of speech or how people feel by them(being confused as to why not everyone automatically accepts and approves of them,and wants to be friends with them or each other)- their are multiple examples of this between the main six,throughout the show

Unusual manner of speech- fluttershy speaks extremely softly and timid. Pinkie pie is overly excited. Twilight can have a very disorganized manner of speech, when in mania.

Rarity speaks like she's from another time period.

Emotional outbursts- the main six have all struggled with controlling their emotions at times throughout the show,acting erratically and having wildly inappropriate reactions to things due to high sensitivity or being so prone to misunderstanding things.

Magical thinking- some of the main six exhibit unusual thought patterns/patterns of logic

This is something that is very common among us autistics.

Infodumping- they all do this. Need I say more?

Tldr: these ponies are autistic,and there's nothing you can do about it.