I doubt they do. But at the same time, I am unclear on how negative an impact it has to model a relationship for them in which the mom and dad never talk, kiss, or act affectionate. And right now, DH goes out in the evenings to the gym or to visit his friends, so most nights he's not even home until 9pm. What would really be different if we got divorced, I wonder?
The economics of your life are likely to be very different post-divorce.
I made a deal with my EXDW to split my income for five years after our divorce (both kids are adults and I help them with graduate school, etc.) If we had gone to court, it is likely I would not have owed her as much support; however, she did stay home for a number of years with the kids and I wanted to make sure she got as good a start on single life as was possible.
One question. Have you considered the fact that your DH may be having an affair? The fact that he is out most nights until 9:00 pm without you (and not at work) seems like he might have something else going on. Best of luck to you.