Short or long action is immaterial, it is the caliber (and energy) of the cartridge that counts. Short action rifles use shorter cartridges, such as the.308 Winchester- an adequate cartridge for elk if the right bullet is used. Long actions use longer cartridges, such as the 30-06- also adequate.
That depends on what you intend to hunt.
surf to the state attorney's general webpage for the state in which you want to hunt and read the gun laws. Always read the law for yourself.
yes
Rifle
No.... You can only hunt with 1 rifle at a time
yes
No
squirrel
shotgun for close range and rifle for long range.
.243
Yes
Some states do allow it.