You're a fine painter. This is a correct sentence; the subject is 'you', the verb is 'are', put together in the contraction 'you're'.
No. The subject is plural (there are two subjects) so the correct sentence would be "David and Jennifer are fine."
Sounds perfectly fine to me.
What is the right page? or What is the correct page? is fine.
Yes, it's fine.
No, the correct sentence is: "Neither he nor you is going to the party." In this case, "is" should be used because neither "he" nor "you" is singular.
No. It has no subject. It needs to start with "I".
Yes, a fine painter.
Yes, that is a grammatically correct sentence. It conveys the idea that the experience has been positive and educational.
The clause / sentence has no meaning out of context. If it is a response, the somewhat archaic but correct construction is "I am fine, as I hope you are as well." You would not use the words "too" and "as well" in the same clause as that is redundant.
chicken man
Yes, it can be correct. It is in the form of an instruction to someone to do something. If that is the context, then it is fine. The context could make a difference.
Add a semicolon after "together" and it reads just fine.