no you can't
Yes, from level 20 on a Hunter can learn to dual-wield weapons from his trainer. You can dual wield any one-handed weapon the hunter has proficiency in. Hunters cannot learn to use 2 guns, or dual-wield 2-handed weapons.
There are always exceptions, but, as a general rule, NO.
You have to earn the golden guns
In the phone book, under upgrades, there is a Dual Wield upgrade for Pistols and SMGs.
Currently, no.
You can do cheats for guns.
I'm an American, I need guns
there are no codes, you must complete the gun challenges
im not necercerrlly sure but i think its hidden and you have to have a donkey
nope.
yes you do at the end you become john marstons son
you can only get golden guns in multiplayer mode