1. Indeed using запятая is an issue. But as I understood some rules:
(a) before что
(б) before он, а etc.

Well clauses are to be separated by comma almost always. So it should be before any conjunction connecting clauses.

2. I didn't understand the comment: "if she still alive". The use of Творительный does it means that now she is dead.

You have used Past tense. "она не была такой..." I proposed Present: "она не такая..." in case if she is still alive at the moment of speaking.

3. Оказалось can be used only as impersonal construction. I didn't know that.

Not only but it is more natural in Russian. It was style impovement (green), optional.

5. I found word радостный and the word возбужденный which also has a different meaning. As I understood exhited it does not have a specific translation

"возбужденный" normally is treated in either medical or sexual meaning.