You sound like you are in a very good place leading up to the surgery. Yes you are right, the pain was definately the tummy area. You will have a catheter till you can get up. I was up the second day i think but I dont remember it, I have seen the photos though of a physio helping me walk with a walker. I do remember being very keen to get up and moving to get the system working again, i was terrified of becoming constipated, more pain. I recall not too much wound pain, but more hassle trying to get organised to go for a walk even just to the loo. all the drains and monitors, the drip etc.
I cant help you about the hair, because i had had chemo and it was just growing back. I do recall thinking it was very convenient in that sense. i had sponge baths each day, but was really stinky by about day 5. I think if i had long hair it could be quite gross. But just imagine how great it will feel to get under the shower when you can.
I didnt have nanna undies, i wore a boy leg low cut undie which was not interferring with the abdo drains. but i was pretty much naked till day 5, just a hospital gown. it was just too hard to get underwear, or clothes for that matter, on and off. when i could I preferred loose stretchy pj long pants, very loose around the tummy, bought them for $5 Big W.
Your hubby sounds great, nice to have such devoted support,
L:)