Opinion on unauthorized UTAU relationships?

Regardless of my opinion, I am not the boss of another person's imagination.

Since you asked, I feel that appeal comes from giving just enough information to stoke the audience's imaginations, but not so much that they cannot fill in some blank space on their own and enjoy themselves. If your description is needlessly specific, it will be hard for me as a creator to want to change that character to suit my needs. It would be better to have none at all, though I'm free to ignore your description completely too.

I agree with Chunter on "not the boss of another person's imagination"

But personally I think it is fine for people to do that, the only thing I'd find disrespectful is someone describing their burning hate for an utau, it's perfectly fine to dislike an utau but one could just put "does not like -insert name-" not "will destroy -name- with the flames of hell"
But in all honesty, I'd find something like that extremely funny

I dont think it is nice. In my opnion, you should ask permission to the other UTAU owner before stating an relationship. For example, most UTAU are friends with Teto or Ritsu and...is it because they are famous UTAU? Or because you really like them? Either way, you still should ask first.

My UTAU, Mougeki Mero is friends with Soho (Sakurai Koucha's UTAU) and Akune Kin (KAI's UTAU). However i've asked permission first before stating relationships, and they allowed me to. I am friend of both UTAU owners AND Soho was the inspiration for Mougeki Mero after all. Well...that is it XD

I find it disrespectful in some circumstances such as "bob-loid hates billy-loid with the passion of a thousand burning suns"
I also think its kind of weird to obsessively ship your utau with someone else's without their permission. (to me romantic/duet covers with another person's utau are ok but going farther than that is eeeeh)
imo if i found someone shipping my utau with theirs without my permission id be a little weirded out but if someone asked permission more than likely i'd be ok with it
whether its disrespectful or not also depends on if you're the breaking rules the creator of the utau made.
sorry if this is confusing lmao

Something like "Utau xxxxx is an idol/is fan of Matsudappoiyo/Teto/Ritsu/any other famous or popular utau" is totally fine for me and I think that there's nothing wrong in that.

But something like "utau xxxxx's girlfriend/boyfriend/villain/rival/friend"... I think that should ask permission first. As long as you have got permission from creator, it's fine.

And writing UTAU xxxxx settings that he or she hates/dislikes other Vocaloid or another utau which is NOT yours is little bit eeeww in my opinion.

I mean the idea is that UTAU's are FOR twisting to your purposes, but unless you're planning on making a long running series or something; there's no reason to describe how the UTAU gets along with specific others in the first place.

To take the bob and billy example, what if i happen to see billy-loid as a really sweet and helpful guy? Then Bob-loid becomes a jerk for hating him so much for no real reason. It serves no purpose for whatever song I'm doing, unless the MMD will be them on stage and the performance is ruined by them not being able to interact with each other due to this hate.

As for how i feel about doing it without permission? Meh, its annoying but not really the end of the world as long as they take the bare bones character into account. Im more irked that it happens at all, with or without permission.