Probably.

Maybe.

They can, but you need to be at least 13 to use/upload on most sites, i mean ppl still lie but nothing wrong with being older /practicing for a few years before uploading and getting familiar with other software

If I were to guess, I would say yes.

Yes, Id assume you can. Although most sites prefer to be 18 and up though. UTAU is indeed a good choice because the software is free and is quite similar to vocaloid. So if one ever decides to start working with the money, I suppose they'd already have some experience in advance.

Utau can be very difficult to use though, so other free programs may be better. I think SynthV is a good choice.

Meiko-lover i got the hang of it, and already downloaded a few voicebanks :))

Alr

An 11 year old can become a producer for UTAU/Vocaloid. They'd better get good at making music and getting their little singers to sing.