For what it is worth, my mother in law always had the inside of her kitchen cupboards painted, both in the house and in the caravan, but it was a long time ago when fitted kitchens were not as beautifully made as they are now.
I think you must ignore it, and the painting, and the mess and focus on you, your well-being and your baby. Seriously.
I don't know how long it is until the birth of your child, but postpone discussions about painting, boundaries and your husband's role and responsibilities until after the birth of your baby and concentrate purely on you. Pass the time by buying those dear little Farrow and Ball sample pots and covering the magnolia wall with colours you might like one day; your kitchen sounds lovely, so take your time to do it justice. Your children will survive your time in hospital; (could close friends help?) then when you are all back together you can decide how to approach the problems with what seems to be your entire immediate family, after you have decided on the decor of your kitchen.