Does the method of building two fences and putting a crate or water barrel in between them still make an impassable barrier?

I haven't tested it out again since the December update, last I checked it did work though. I have seen reports it doesn't work anymore, but that could have been from modding. Worth a test just in case and either way you'll be wanting a layer of tall walls around your spot.

You want televisions.

It's still somewhat works. But when you are at a certain distance from them, the zeds will start hitting the barricades anyway and eventually tear down your walls.