I have several questions about the download process for new games. My computer is having trouble loading the stcky page for downloads so any help would be appreciated.

I am going to purchase the download only expansion bundle so..
( I have galciv2)

What programs, if any, do i need to complete the download
Will I be able to download the expansions multiple times(in case i have to uninstall the expansion or get a new computer)
Also, is there an exact release date for the newest expansion, and if so will i just gain access to the download the day it come out?

Thanks