airlines and equipment...the rules are very strict because there are none of old flexibilities left in the system. People I know who used to tip the skycaps and get 20 cases on a plane are now shipping them fedex.
Whatever fits into a carry-on is okay. But you are limited to one and a small handbag – laptop, purse, whatever. If you travel business class you can bring a second carry-on. My advice pack light or ship it ahead. The bag fees get expensive if you do multiple hops.