The midwife recommended coconut oil to use to me, I’ve been using it twice a day and noticed a massive improvement
I wouldn't use moisturiser as their skin is quite sensitive. With my first baby a midwife suggested olive oil and this did help, I've also heard people use coconut oil. And a lot of people suggest breastmilk, I have some colostrum I harvested whilst pregnant I might try as my baby's hands and feet are very dry.
I use vaseline to massage her after a bath which is usually twice a week.
Leaving it be - it’s normal as they’re used to being in fluid in your tummy, it’ll flake off and should balance out