The anti hijack locks doors at 10mph, you should be able to open any door from the inside only and as you say if you take the key out.
Diagnostic vcds might not find a fault if there is still power to the switch. Check the users list in the vag com forum. For someone near you.
With regard to buttons not working, I had my centre console out to fit cd changer, the button can come apart quite easily although still connected to the loom.
The back of the centre console pulls off, quite hard to do as not much space to yank it.
Two torx screws under there then two at the front and you can lift the lot up and get the whole window switch and cigarette lighter unit out. Feel underneath at the front of the console switch unit and there is a tab that you can push back to get it out.
Hope that helps. I doubt the switch is faulty, just contacts might need a clean off.