Yes You can
YES
no
No
its carry on luggage isn't it?!
Not as a carry-on
you cant take javelin to an airport they will take it
Yes you can put a skateboard in a luggage that is not a carry on.
No, you have to take an emery board one.
You can take a small carry on and a bag you can check. Most of the airlines will charge you for a second bag that you carry on. I was using a small backpack last summer as a carry on and American Airlines wanted to charge me for it. I told them it was my purse and they didn't charge me. My sister had them try to charge her for a small bag she had around her neck to carry money in.
A carry on luggage basically is a bag that can be carried and bears the size of a bag that can fit inside the luggage compartment of the airplane.
for carry on you can take one or two carry on. For checked in, as long as it is within you allowed weight.