It's nice, but I think you should try it with photographs instead, it never looks quite right with just speeded up video.
You can get away with it with the shorter time lapse, but you are definitely right about the longer ones. I haven't checked yet but I am wondering if the Phantom standard has an interval shutter.
I don't know, but the other p3s have it. Lowest is every 5 seconds though, which would be ok but with only 20 minutes flying you end up with just a few seconds at 25 fps.