If i have an album in lossy gapless files (Ogg Vorbis, Musepack, LAME Mp3s or Nero AACs), is it possible to write them to an audio CD, and have gapless playback on the CD as well?

If it is possible, how do i do it? Is it enough to just add the lossy files in Nero and set the pause between tracks to 0 seconds? Or should i decode using Foobar 2000?

Nero's decoding filters should be able to properly handle Vorbis and Musepack, I'm not that sure about AAC, but probably won't be able to gaplessly decode LAME.

So how can i burn a gapless audio CD from LAME Mp3s or Nero AACs then?

I believe you've already answered this question in your first post --- you can use foobar2000 for example.