Just do it through Amazon. They don't charge till the game ships.
Yeah you can absolutely customize your Agent. From character creation to what they wear. There are 3 weapon slots (primary, secondary, sidearm), six stat changing armor slots, and six cosmetic slots. Cosmetic slots layer so if you have say body armor on, your jacket will go over top, or you can completely unequip the jacket and just rock the body armor. They want your Agents to be unique to you. There's also male / female, different hair styles, facial features, tattoos, ect.. List goes on.
Yes on Amazon.
Great,
I preordered through Bestbuy, said up to 72hours, and Amazon said up to 2 days.
I did with BB since I have GCU. But pending beta, we'll see if I keep it.