They said things like what is written below…:

Last week, the illustrator of my live 2d model, Testu no Kusari, drew illustrations foron my commission live on YouTube.

The appearance of her character is kind ofsomewhat scary and her comments on Twitter are very chaotic sometimes, but she is a really nicekind and interesting person.

Your sentence is correct. This is just another way to say it.

I ordered three line art drawings and one icon pic ofor the face of my live 2D model.

Fortunately, I could join and stay on the live stream from start to end, so I communicated with her and other viewers through thein chat.

It was interesting to hear impressions ofwhat people thought about my character by others.

This is more how'd we say it in the US.

They said things like those below…

-He is like a character who bothers a heroine at the beginning inof an anime.

へー、失礼。

-If he wasere in a band, he mustwould be a bassist!

I realize someone else wrote this but I wanted to point out that this sentence should be subjunctive case.

賛成した！

Last week, the illustrator of my live 2d model, Testu no Kusari, drew illustrations for mythat I commissioned live on YouTube.

The appearance of her character is kind of scary, and her comments on Twitter are very chaotic sometimes, but she is a really nice and interesting person.

I ordered three line art drawings and one icon pic of the face of my live 2D model.

icon pictures are usually of the face, so while specifiying that it's a picture of your character's face isn't wrong, it sounds unnatural.

I told her that she could draw them on her live stream if she wanted when I commissioned her to draw them.

Fortunately, I could join and stay on the live stream from start to end, so I communicattalked with her and other viewers through the chat.

It was interesting to hear the impressions ofthat my character bygave others.

They said things like the sentences below…

-He is like a character who bothers a heroine at the beginning inof an anime.

-He looks like a villain who talks in a femalinine manner.

The appearance of her character is kind of scary, and her comments on Twitter are sometimes very chaotic sometimes, but she is a really nice and interesting person.

The three line art drawings awere for reference material.

The past tense seems more appropriate here.

I told her that she could draw them on her live stream if she wanted when I commissioned ther to draw theming.

Fortunately, I could join and stay on the live stream from start to endfinish, so I communicated with her and other viewers through the chat.

Usually people would say "start to finish" or "beginning to end"

It was interesting to witness thear impressions of my character bymade on others.

"hear" suggests others would be talking in the live stream too, if that is correct then there is no issue with it
Otherwise "witness" is more neutral as you could also witness the live chat messages etc.

They said things like below…:

"like" could be replaced with "such as" to make it sound more formal, but I doubt that is what you are going for here so it is all good :)

-He looks like a villain who talks in a femalinine manner.

-If he was in a band, he mustwould be a bassist!