Naming Conventions: German Ancestors

Quite selfishly I need to understand better how to input data for my German ancestors.

1. What is the historical period break out / change? For instance, English conventions changed a couple of times: with the adoption of surnames (ca 1200s); with the adoption of middle names (ca 1700s). But my understanding is that this may be different in different countries.

2. What are the rules for baptismal names?

3. What are the naming patterns? (a sub paragraph, I know, but would be helpful for me: for instance, if the convention is that "families may have used Johann as the first name for multiple generations" that is helpful to me).

4. What were the "usual" ways names were anglicized in the United States? (another subparagraph)

5. How do German Americans names now differ, if at all, from names in Germany?

6. Appropriate citation data welcome.

Available fields:

First Name
Middle Name
Last Name
Maiden Name
Display Name
Suffix
Nickname [to be relabeled 'also known as']
Birth name [to be added; use in "about me" in the meantime]
Title
Prefix [to be added; use in "about me" in the meantime]

I spoke re Customer Service about this for their direction - has this question ever been answered?