Not sure who's answered these already, but here's the answers to a couple of your questions about the door handles:
1) To hsvae them,normally the handle is taken out and the relay for the remote pop is installed. a small piece of sheet metal matching the hole is welded in, ground down, smoothed out, bondoed, and primed to be 100% smooth with the existing door panel.
2) There is a relatively generic door opening kit you can purchase (generic meaning it will work with almost any make/model). The relay and actual latch release are installed before the sheet metal is welded over the hole, and you can just use a remote similar to an alarm to pop the door open.
By the way, most people choose to install a manual open button for the door underneath the car or deep in the wheel well, somewhere you can get to if the remote is broken, but it ain't gonna be clean.