Wow, sounds like our house about...2.5 years ago.
Anyway, I left for much same reasons Dr. Scientist is thinking of leaving and if he wants to bounce anything off of someone two years out of the academic world from at least a similar area and who he doesn't live with/work with or used to work with, I would be happy to chat.
Ouch.
Academic teaching jobs? Ha-ha-ha! Also? HA!
ILs? Not that this will make you feel better, but it took my spouse over five years after the first kid to learn to filter his mother properly. And he still slips up, sometimes. Not that this is any kind of a consolation to you. But you know, I am all about honesty. Especially when I am a margarita and a half to the wind.
Ok, just me maybe, but perhaps he should not make any life changing decisions while sleep-deprived and with a new baby.
It's just kind of a shock to the system when they arrive, so changing even more? Meh. Can he wait to change this aspect until the babe is a bit older? Like even six more months?
Sorry about all the frustrations. 
Feel free to vent anytime...it makes the rest of us frustrated people feel less alone.
That was our house a few months ago. We were in total chaos - no one was happy. Then, once the baby started sleeping in longer chunks of time, we started coming back to our senses.
If thinking what would Dr. Laura say... Maybe if your ILs bother you, just be direct and tell them what you want, with your husband standing next to you and with his full support. The ILs are privileged to spend time with the baby, and should respect the ground rules for your household. You are the (mother) gatekeeper.
It's only really a problem with the ILs when I'm not there. I'm there and he cries? I say "Give him to me." Sigh. He'll deal with it eventually, I guess.
The Pumpkin usually sleeps 7 or 8 hours (!) at night, which is kind of amazing. And yet, we're tired. How is this possible?
Henry, I think I will put you and Dr. S in touch; it would be good for him, thanks!
The spouse is mostly now doing the look-at-job-ads stuff, and is trying to finish his project so that he'll be free to leave when he wants. Aurelia, I hope he'll think about it a little more before abandoning ship entirely. Babies are very disrupting indeed!
I agree that this isn't a wise time for Dr. S to make life changing decisions. Our household did fine until I went back to work, and then Husband and I experienced 2 of the most difficult months of our marriage. But you get into a routine, you all start sleeping a bit more, and things improve.
It gets easier, I promise. It's hard when everyone is tired, no one is getting any "me" time, and the baby still needs you so much.
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