If the returns are constant to scale, the output increases by the same as the increase in inputs, therefore, it would double.
Depends on if you've got it on PC or console. The console versions obviously work on the latest generation machines and come with the texture pack (which has always been free), modding capabilities (better on XBONE) and all DLC's.
So if you're looking to take your PS3/XB360 copy to the next level then I'd say yes, personally.
The PC version gets you the DLC's thrown in and that's all, assuming you don't own any of the DLC's this might be he better value overall depending on offers, so do some research, you're not gaining anything bar the DLC's though, you could already get the texture pack and mod.
Short answer: Consoles: Yes. PC: Only if the DLC's are cheaper that way.
I would say people who do light steel usually redu things and carpenters can build at structure from scratch. And light steel specialists usually just work with light steel as those who are carpenter specialists usually work with many products.
I hope this helped.