Improved Races isn't recommended to be used with LU (there will be some incompatibilities somewhere), but the OCV and the Phanon corporation make enough trouble, let alone other races having war as well.
As for the 'enemy' races, they are much more active in LU than vanilla, however they won't take over sectors.
Jack08 said he *might* make an Improved Races mod tailored for LU, however if he did, it would be far in the future.
However another feature that is coming to LU very soon that shall add a bit more life into the galaxy is the new mission system, that will grant missions based on universe events.
The ETA for this is 2 or 3 weeks, so it's not a long wait.
If you want to read a bit more about it, look here:
https://code.google.com/p/litcubesunive ... i/EMS_Home
Personally I recommend LU as it is still in very active development and new features are being added on a constant basis, so it is only going to get better (it is very good right now), whilst XRM is pretty much done except for the occasional bugfix. That doesn't mean XRM is bad, it is a very good mod, however it is pretty much near the end of its life.
1940s - Various "computers" are "programmed" using direct wiring and switches. Engineers do this in order to avoid the tabs vs spaces debate.