Please help me to understand draught beer better:-

01) The kegs of draught beer are already carbonated before they are distributed to end users - true or False

02) Kegs of draught beer are always artificially carbonated (usually in bright beer tanks after which they are kegged) - How far is this statement accurate

03) When gas CO2 or CO2 + N2 is used to force the beer into the spigot pipe, does any of it dissolve into the beer giving it more carbonation and if so is this increase taken into account when carbonating kegs in the brewery? What would be the percentage increase, if any?

04) Are cask conditioned ales also considered draught beer? how are pulled from the casks ?

Thanks