Don't eat it. It has started to spoil. If the container is unopened and you have handled and refrigerated it properly, return it to the store. Fresh mozzarella does contain bacteria and usually has a very short shelf life. It may or may not be safe, but there's no way to tell and you probably would not like the flavor.
Yes, that is safe.
That could depend how far past the sell by date it has gone. Whether or not you should eat it will be your decision.
Yes, fresh mozzarella does melt when heated.
Yes, fresh mozzarella will melt when heated.
I would eat it up to about 10 days after if no sign of mould
No it isn't.
mini fresh mozzarella balls
Yes it is safe.
I would not eat it, who knows how many flies have been on it
I would not do that.
If it is fresh pineapple it should'nt be fermenting so the answer is no.