Hey there.
I can sympathize with your situation because I went through the same thing. School gets somewhat better after first year. It will still suck up a lot of your life, but not as much as first year. The main problem with first year is that you have no idea what you are doing or how much to study. Thus, like most risk averse lawyers, you overstudy. That will change with time.
As to working as a patent attorney . . . the hours really don't get better. If you are 80% efficient as a prosecution attorney, you are doing pretty well billing your time. I'm not sure what your firm policy is like, but when I was a first (and second) year, the partners in charge of my clients told me to bill 100% of the time I spent doing anything for a client. They would work out how much the client was actually billed. It wasn't until I was a third or fourth year that I was expected to limit my billable hours for particular actions. Also, it would seem that at least some of the stuff you consider non-billable (e.g., checking IDS' and other paperwork) is actually billable. You are providing a value added service to the client. Whether that time gets passed on to the client is the responsibility of the partner. You shouldn;t cheat yourself out of 1-1.5 billables a day because you feel altruistic.
Regarding your marriage, that is a tough one. Working full time and going to school at night sucks up a lot of time. Your wife needs to understand that you are trying to provide a better life for everyone in your family, and that the ridiculous hours will eventually end. But you also have to understand that your wife and kid need you around. My suggestion is that you schedule 1 day a week, preferably a weekend, where you spend the entire day with your family and do nothing else. I did this, and it was the single best thing I did for my marriage while in law school. If your grades slip a little, so what? Who gives a rats patoot if you graduate cum laude if you are divorced and are paying child support? I doubt many people would consider that "succeeding" in law school, and any human attorney you work with should understand. And if you work for someone who doesn't understand, run very very very fast in the other direction.
Best of luck to you. Feel free to PM me if you want to discuss in a less public manner or just bounce some ideas off me. Happy to help in whatever way I can.