I will be in Japan this December, starting in Tokyo and more than likely traveling to a few other cities. I want to pack as light as possible to avoid having to cart big luggage with me onto trains and subways. Thanks in advance.

TSA says "Carry-on baggage is a small piece of luggage you take onboard the airplane with you. You are allowed one carry-on in addition to one personal item such as a laptop computer, purse, small backpack, briefcase, or camera case." I don't know if the camera case is like the big ones the size of suitcases or does that also include the little small ones that just holds the digital camera. Cuz if I can't bring all three I'll just put my digital camera as is in my boogbag and just be extra careful.

I am traveling through Italy by train (public transportation) to Milan, Venice, Florence, and Rome. What type of luggage do you suggest, a hiking backpack or a rolling suitcase?

I'm trying to pack light, and I've squeezed everything I need into a backpack. I suspect the backpack will be too heavy to be carry on luggage. Do you think it is safe to check in my backpack? Will it get lost? It's a slightly bigger than usual L.L. Bean backpack. Should I just pack everything into a huge suitcase instead?