Yes you can,
You can pack them in your checked luggage, but you cannot bring them with you on the plane, such as in pockets, purse, carry-on bag, etc.
Well, it is a chemical but non-hazardous. If you put it in checked luggage there should not be a problem.
Yes. I have carrried one in my carryon and checked luggage for international and national flights.
Checked luggage is that which has been checked in: weighed, labelled, and taken away to be loaded onto the plane. You don't see it again until you have landed at the other end and the plane is unloaded. Hand luggage is that which you can take onto the plane with you and have access to during the flight.
No, they must be in your carry on luggage.
If it is in your carry on or luggage.
No Australian quarantine laws are very rigid if you do bring any food with you declare it at the point of entry or you could get a fine
No, only if its cargo checked you can
It can be transported in your CHECKED baggage after you declare it to your airline. It cannot be carrried aboard by you. Check with your airline.
Plane-side is a derivative of gate-check in terms of luggage. Plane-side luggage is generally used to describe luggage that was gate-checked, but left on a designated cart next to the stairs of a small aircraft. This cart of luggage is then taken and loaded into the cargo hold of the aircraft. Upon arrival, the luggage is taken off first and carted to the aircraft stairs for passengers to retrieve.
You certainly may take nail polish in your carry-on or checked luggage. . It is specifically named as ok to bring. People like to be alarmists and say you can't bring this or that and simply do not read the TSA information. There is tons of misinformation on this subject.
While I haven't seen it on a TSA list of restricted items (although it could be, as I haven't checked that list in some time), it is an item which, if you tried packing it in your carry-on luggage, is going to raise concern and possibly cause difficulty for you. If you're gong to bring it, you're best to keep it in your checked luggage.