Not likely, the bend of a AK-47 magazine is too great for an AR. One from an AK-74 might work as it is closer in caliber (5.45 to 5.56) but to be honest I don't own a -74 nor an AR so I can't say for sure. I just know for a -47 it isn't normally a match, but much of it depends on the pouch as well...
Yep. I have a few pouches that will fit AK47 and AR mags, but it's very dependent on the maker. My "go-to" harness is a TAG Phalanx and it'll hold AK47, AK74 and AR mags neatly. Some of the cheaper ones will do it, but they are a sloppy fit for AR mags.
Usually, yes. Just keep in mind that it works better if you run the mags with the top up (the opposite of how AR mags get stowed). It keeps the tab from hanging and even ignoring that, woks better for the way an AK gets reloaded.