Ahh good girl Sophia 
Alex, he's against it because it takes longer for me to express than to make a bottle of formula and he doesnt like the fact that I need to express before we go out etc. I've gotten into a routine but he finds it limiting I think. Just cant please him at times! He was all for it in the beginning as he wanted to feed H, but think the novelty has worn off now.
He used to love giving him a bottle so its a bit sad really.
Babies are much better at getting milk from you than a pump is so Sophia should always be able to get enough from you without an extra bottle of expressed. If you do want to try expressing though I would say to try after she has fed initially and see what you get, if that doesnt work, try expressing 2oz before a feed, it will be easier before a feed as you'll be more engorged but Sophia will be better at getting milk out so it should make no difference to her.
I had to use nipple shields to get H to BF so never had any issue with nipple confusion as they probably felt similar, he would go between bottle and shield without issue, an still will. He will also latch breifly after I've expressed as the pump has by then given me mammoth nips 
They do say to leave it till 6 weeks to introduce a bottle but I know people who have done it before without issue. If it is one bottle a day or every other day I doubt it would cause an issue, I dont have much to base that on though.
Glad you are feeling better, I find I can function pretty well on 4 hours sleep now where as a few months back that would have been torture. If its 4 hours unbroken that is, waking every 1.5/2 hours is still a bit of a killer.