Second: Why is your AK... your back up gun?

It wasn't, at least not intentionally. It may very well have been his primary rifle, but it's not what he had on him at the time.

From the article:

The homeowner was present when the three men entered the house and pulled out a handgun from his waistband, but dropped the firearm.

You want him to stick an AK down his pants? I mean, this is Florida Man, so it's not out of the realm of possibility, but still.

Also, it's already been said, but dude seriously could use some training. Glad he's alright, but what a clusterfuck.