As I said, I don't believe it to be perfect, but I have severe doubts current powers could come up with something better.
The question of the number of representatives by state is a political one. Look at the EU. Pretty much the same. Otherwise a union would not be possible. This is a form of minority protection. There is valid criticism for that but said criticism should first understand why it is the way it is. There is also valid criticism of "the winner takes it all" approaches of course. These issues aren't even disconnected here.
Still, the US constitution is pretty great. I don't know of one that is better. I don't believe the current political climate could improve it significantly and I cannot blame it for not having a direct answer to any legal question. A constitution that might have that would be extremely long and probably extremely bad.