I will reply to two of your questions.

3 - Were all the Louisiana units recorded and documented in the French language? (Coming from Switzerland French had to be one of the languages Wirz spoke.)

No. While there are cases where French was used in giving commands to members of a single company of a regiment, I am unaware of any regular regiment composed entirely of French speakers. This might only have occurred in the Louisiana militia. All official documents were in English.

4 - I imagine many Louisiana units were strictly composed of Europeans?

Not at all. As stated above, only a few militia units were composed entirely of certain nationalities, and they were not all born in Europe. Most were the sons or grandsons of immigrants from Europe. I am unaware of a single unit anywhere in the Confederate army composed entirely of Europeans.