How do I model data from arbitrary CSV's in a database?
The question is so wide open that it is hard to say much.

And why are you using a database at all? Excel does everything you've described so far.

Seriously though, avoid making an inner system in your database that can store any kind of data. You have one already, called a DATABASE. Make code that creates the tables you need. What's so bad about that? I say option 1.

You know, if you want infinite flexibility how about a square-mile white board?