So I think the ponies are a pretty good art style and it would be great for a pony-styled keen mod. I think it should be about keen visiting equestria (the magic alien horse kingdom) but some bad stuff happens and the ponies get kidnapped so keen must turn himself into a pony that shoots zaps out of his mouth to save the kingdom from the other non-horse aliens or that black witch horse. because. It is good.
Frankly I prefer the G1 series and especially my Little Pony Tales. MLPT has everything the current series is lauded for and more.
The ponies don't just do girl stuff, they start a business (that is then ruthlessly crushed by unscrupulous competition.), they care for the environment (after being shown they screwed it up.) heck they even violently attack a family they think are burglars breaking into their clubhouse.
The series has a strong focus on relationships of both the non and romantic kinds (something bronies seem to want to force into every orifice of G4.) with the take home message that they're not as simple as you'd think. (The second makeover in the series fails HARD, teaching us it's better to be yourself than what others want you to be.)
There is a strong contingent of male characters of all temperaments.
There is only once princess in the series who is a side note in an episode that teaches a lesson on adoption and families.
What you really need, not what you think you ought to want.