Je unapenda matufaha?
Unapendaje matufaha MAHIZI?! >D
"These apples" = matufaha haya
Mahizi isn't a word.
do you always have to put "je" in a yes no question?
You don't have to, but it is a good way to make the sentence clear.
The "proper" way is to put it there, but it is pretty uncommon in actual speech. So no, you really don't have to. It might be more common in writing, but I don't know if that is true for sure.