,,Is that a VOCALOID?''
nope
,, What the hell is she singing?''
A Japanese song in Japanese. You wouldn't understand even if it would be in English.
,, Why does she look like/sound like Luka/Miku/Rin/Gumi?! Are you stealing their voices??!''
Look at the title please and go google it. And, what, can't other non-fictional characters have pink/blue/green/yellow hair without you coming in here and being triggered and having a major childish tantrum? You can go back to playing Pokémon.
,, Why is she singing so low? What horrible singing.''
Not as horrible as Justin Bieber's/Ariana Grande behaviors to other people. At least, mine will not hurt you or worse. (you decide)
And a possible scenario that can happen:
,, Hey, that character is already made from someone else! You're stealing/taking credit that isn't yours!!''
Eh, excuse me? It's MINE. So, if you can kindly give me the link to the one who ah a 'similar' character than mine - I would like to have a chat with them and call for reinforcement.