Don't know if I can answer all of your questions but I will try!

1. The physio at the hospotal said after 6 weeks we could resume exercise assuming that we could so star jumps without weeing! I gues it also depends on the actual birth and how easy/hard it was.

2. No idea but I did read a sign at the airport that said you can't take babies under one week of age which makes me think you can take them if they are older.

3. I don't think there are ny rules about newborns in theme parks - just your discretion about how much sleep they will get and if the facilities are up to scratch

Hope this helps! We tooke our 7 month old to QLD recently and went to Seaworld - she slept in pram and we changed her on the grass (well on change mat and it was sunny!). I fed her where I felt like it!