I do not think "Yeye" is gender specific. My understanding of the word is that it means "That one (or that person) ..."
both he and she are accepted
How do I know when to use M and Wa in a sentence ? Like Wachina and Mchina?
Use M when it's singular and wa when plural
For example mimi ni mchina (I am Chinese)
Wao ni wachina (they are Chinese)
Why are there no sound?
I hear sound now, but it doesn't sound like it's been voiced by a native speaker
I am. Some people roll their Rs, others don't