yes the are called the siamese fighting fish for a reason
yes, currently most of all the betta fish come from china. they are found in little ponds with other betta's.
Yes, Betta Fish are extremely aggressive and they will most likely kill your other fish.
Yes they would be fine (if they are plants that are ment to live underwater) for the betta splenden aka Siamese fighter fish (assuming that is the betta you are refering to) as it is a tropical fish
yes the most popular fish :)
sleep
Most fish get along well. However, do NOT mix betta fish with other fish. Not even another betta. You have to have a permit to have to betta fish in the same tank with eachother. Betta fish are only mixed to mate. Bettas are not born in the egg. They come out as a very small fish. After the betta babies have come out, all of the fish are seperated. Even the parents, if the betta babies are left in the tank with the others the betta parents are very likely to eat the others.
Some are, most are not.
Male Betta splendens fight with other male Betta splendens so the answer is most other fish will not fight with a Betta in the same tank. To try to list every species of fish here would be impossible.
Probably the king betta because it's the largest and in most cases the larger the fish, the smarter
Betta
most likely around 4 inches
Yes betta fish do have bones like most other fish.Yes. All beta fish have bones. Unless it was born without them then it would just be a fishy blob.