It turns out that the outside door locks of my new toy don't work. The key inserts too easily, and it won't turn.. It feels like the tumblers are stuck pushed out -- I don't feel the tumblers when I insert or remove the key.

I was able to get the trunk lock working again by squirting penetrating oil into the key hole, but the door locks are resisting that trick. So, it looks like I need to remove the outside door handle assemblies and disassemble and clean the locks.

Can the door handles be removed by just removing the nut just inside the rear door edge? Or does the door panel need to be pulled to access more bolts/nuts inside the door?

Any other tips or suggestions?

Try this:
http://www.914world.com/specs/rebuild_a_door.php

Yes, there's a socket heat bolt hidden behind the door panel, you'll need about a 6" extension using a 1/4 or 3/8 socket wrench. and a light to find where to get at it.
It's either a 5 or 6 mm hex.

5mm hex, easy to find and remove.

Thanks for the link to the article. That's great!

How does the inner door panel (door card) come off? Just pry it off, or is there a trick/tip for that? Anything to watch out for?

Pocket handle comes off with 5mm hex and phillips screws. Door opener/lock and window winder come off with phillips. Door card has about eight snap in fasteners around the bottom and front (of the car) part of the panel. I use a small plastic pry bar for these, as you don't want to break them off. Top of door panel pulls up and off. Look up inside of the door at the door lock with a flashlight, you'll see the other 5mm hex bolt there.

Excellent info., guys.

I see another project in the line-up here.