Questions about Steam

[Kamog]

With SEV not available in local stores at this time, but available through Steam, I'm starting to wonder if getting the Steam version is a good idea. I would prefer to get the boxed version that comes with a printed manual and CD, but if the stores around here don't sell it, then Steam would be an alternative. How does Steam work?

If you purchase SEV through steam...
1. Do you need to have internet access every time you want to play the game?
2. Is it possible to install the game onto a computer that does not have internet access?
3. Do we need to leave the "Steam" program installed on the computer to play SEV?
4. If you replace your computer in the future, would you be able to install your copy of SEV onto the new computer?
5. Will it work with dial-up internet?

Thanks for your help.