Hi Gazman,
yes, there are commuters, my guess around 70% actually. And yes, there is an Interline agreement with LUXAIR ID90, don't bug me if there is a 6 or 12 month waiting time after you join, but I think there is not.
However, the company isn't too happy about commuting, simply they don't want people to show up after 6-8 hours driving or flying in, being tired and then going on duty. Life is a lot easier if you live close by. Guys who seem to be not flexible in the interview when it comes to the question of moving close to LUX seem not to pass the interview! However, what you do after you are hired and in your off days is up to you.
My recommendation is: If you live further than 2h drive from LUX or if you have to use a flight to get there, and you choose not to move close by, get yourself a crashpad either in LUX or on the german side (Trier) which is a lot cheaper and only about 25 min. to the Airport. People also share apartments, you'll use it 2-3 times a month.
This way it is easily possible to commute bearing in mind the time you loose being on the road then.
F/O's salary is good enough to make a living even in the first year, and if you hold some experience before, you'll slip into the SFO's payscale after one year and that Porsche won't have to wait for you in the cardealers window for too long anymore......
Anyway, good luck to all and maybe see ya on board.....
WOB