Do we have the tools already to mod a weapon in such way that it is improvable with your smithing skill? I would love to use this weapon but it is not worth it since I can't upgrade it. If anyone knows how does it work in the files, would you be so kind to provide me with such a tweak?

Nope, not yet. Once the construction set comes out we will.

Oh.. but as far as I remember, skilled modders created such tools before the official mod tools were released for f3. Any chance those will work for Skyrim?