none of that helps against a compromised machine.
Actually, it does.
You may fool an attacker into thinking that he hacked all the layers, while he only hacked top 2 of them.
Maybe we are misunderstanding eachother, but what do you think gets captured by a keylogger running on the *host* where you open a VM in a VM in a VM via a VNC session and you type in a TrueCrypt password, anywhere? Bonus points for guessing the same for what happens if you press PrtScr.
Actually, i meant VNCing to the VM from a laptop.
VNCing from the same comp would have no sense as the keyloggers/screen capture/mouse movements capture would kill it.
But VNCing to the bottom layer from outside should be safe enough.
A hall of mirrors is so Commodore 64 
The object of security is not complexity, in fact the simpler you can make the more secure, because the less components can contain additional vulnerabilities. This happened: firewalls containing problems which made the machine less secure than without them. Virus scanners that kill your data due to false positives etc.
The object of security is not complexity, in fact the simpler you can make the more secure, because the less components can contain additional vulnerabilities. This happened: firewalls containing problems which made the machine less secure than without them. Virus scanners that kill your data due to false positives etc.Well, i didn't say this is the most secure way, i just said it is more secure than having single layer protection on a single computer.
The "separate minimal machine for Bitcoin only" is of course superior to everything.