Ok I got it running! It actually was the "-noserversend" argument which I had in the lair2.commands file. As soon as I remove this, DL2 runs just fine, both from command line and from ES. (I think the command line from my post above was wrong and did actually not include -noserversend).
Interestingly, I use -noserversend in other command files and there it does not seem to cause issues. Anyway, thanks for helping!
