I've never played Elite however I did play a game called Hardwar ages ago which is in a similar mould and was a lot of fun. I haven't played it recently so the graphics are probably looking very dated now.
On the Total War + nation strategy game I think there would a number of problems trying to fit in the part of playing battles. In the later Total War games you need to control every battle which time wise would exclude a lot of people as an average game of Civ already takes a lot of time. There is also the risk that one part of the game would have too much impact, either playing battles makes wars too easy or nation tech / resources may be the controlling factor and make the battles pointless.