There is a macro file in the WTF folder for each account. You can copy this.

Bindings and bars are a lot trickier. It depends if you use an addon as well.

For example, my entire wow crashed last night, I lost everything and had to end up deleting the WTF folder. 7 accounts, about 25 characters total took 3 hours to re-setup. It is a lot of work. But it is work that you will only have to do rarely so I would recommend taking the time to do it by hand and make sure it's correct.

Depending on how you play, I operate my copies of WoW stacked on top of eachother. At any given time I can only see 1 and it's running at 1440x900 windowed on a 1680x1050 screen. If you are operating only the main and have the other 3 followers, I am not sure what you would need to have them visible on the screen. Just switch between active copies of WoW when you need to switch chars.