hey !! aww thank u ;; i’ll do my best to answer! but i wanna start by saying like My Opinion Is Not Law and im just a dummy on the internet so u dont have to totally agree w everything i say kjsdfjkhs but on the other hand ped/ophel/ia is not much of an argument and it IS a matter of right and wrong, so i go with my gut and my morals. and i’m glad you agree with that!

also sorry this gets a bit long i wanted to really flesh out my thoughts so they make sense. i hope they’re easy to understand but if u want a straight answer just skip to the end.

CELESTIA; i don’t feel that its safe to ship celestia with any of the mane 6. she’s really superior, and at least 10000 years old? (according to the premiere). she holds a lot of power over the rest of the cast and seeing as she knew twilight as a child (and for the rest of her childhood) she hypothetically could have known the rest of the gang too? also they grew up like, under her rule, in her kingdom, knowing her constantly as an Adult. 

LUNA; luna is a bit more tricky because she’s also somehow thousands of years old, but younger than celestia, and she was banished to the moon for a thousand years. so none of the mane 6 (or any of the regularly-aged ponies in the kingdom) knew of her for a thousand years. they didnt know her/of her while they were growing up, and only met her as grown adults. she does feel somewhat less superior than celestia, but the other ponies still look up to her and respect her stance as being like. Royal and Powerful and, well, Above them. BUT - she’s a grown adult in equestria girls while all the others are literal highschoolers, so i think THATS a pretty clear no-no.

and considering equestria girls is throwing a whole ‘nother wrench into the mix. because i pretty firmly feel that the mane 6 are like young adults in mlp canon (they have jobs and their own homes), but in eqg theyre teenagers.

im p sure that eqg decision is just to appeal to young girls in the franchise (its easier to relate to and explore the worlds of teens in hs than it would be with young adults), but making celestia luna AND cadance all adults is kind of telling on their power imbalances, i think.

CADANCE;  it’s hard with cadance in the mlp canon because i think at Most she’d be like … 10 years? older than twilight (and the mane 6)? thats just how it Feels at least. since i think she was probably a young teenager when she babysat twilight, who was a Little Kid. so i think you could like “Get away with it” in mlp canon as long as whatever member of the mane 6 (excluding twilight who, aside from being her sister-in-law, she has known since she was a child) who ur shipping her with is also an Adult-Adult. if that makes sense.

but i would go with my gut on this one and refer to equestria girls. like, despite the Canon “Ages”™ in the ponyverse, the fact that when put into a world of human equivalents the mane 6 are teens and celest/luna/cad are adults is. a statement! theyre not of equal footing. theres a certain power imbalance and they would not have healthy romantic relationship dynamics.

TLDR; my Official final stance on all this is basically: No. i wouldn’t ship them with any of the mane 6/etc. maybe an exception for cadance if its some au and the age difference is not a severe imbalance (ie. theyre both adults) but thats kind of a stretch and unnecessary so i’d just. Not. you know. its not that hard to Not Do That.

i hope this helps!! it is just my opinion, but i really think the equestria girls comparison is kind of pivotal and important to consider. and you know, usually when you have to question something like this and find “evidence” as to why it might NOT be bad, or w/e, thats kind of a bad sign. just something to keep in mind !!