There are regulations on mirrors. Not only here but over seas and they have said they want to sell this car all over the place. Mirrors are the cheapest, most reliable, highest resolution monitors you're ever going to find. Simply by moving my head, I can get alternate views, tougher to do with cameras. Yeah, there's drag involved but probably not all that much because they're pretty small and their placement is where the slipstream has already separated by the windshield, so their cross section is only partially causing much drag.
As to the door handles, we don't really know what they'll be like until we see the production concept. However, traditional door handles are cheap, reliable and create almost no drag, so I don't expect see any high tech solutions here. They do need to keep costs down. I am hoping for something kind of stylish though.
"Beer, the cause of and solution to, all of life's problems." -Homer Simpson