Was .NET All a Mistake?
I think you put the case too strongly, although I see where you're coming from. It also seems to me that .NET refuses to play to its own strengths, and consequently does some things pretty well while really excelling at nothing.
The high resource requirements of .NET apps are, in part, because they're not interpreted, but JITed, after all, just like Java. If .NET were interpreted, .NET apps would probably be much lighter-weight.
Was .NET All a Mistake?
Garbage collection is such a huge win, I'd be willing to pay almost any price.
But why does it require a complete virtual machine system, and all the weight and complexity that implies? It's my understanding that there are compiled languages that support garbage collection.
The other advantages you list should be possible through the development of new libraries, new languages, and through evolutionary development of the existing Windows API.
I've never understood why MS went to the bother of building the VM without actually porting it to any other system.
Look For AI, Not Aliens
If one's human personality is migrated to a machine, then adjusting one's subjective timescale should be trivial. This would allow for subjectively fast travel or even (with a total shutdown, a cybernetic version of suspended animation) subjectively instantaneous travel. Subjective travel time becomes zero for all distances.
Creating perfect copies of one's personality, memory, and current emotional state also becomes trivial, which means one wouldn't even have to decide between staying here or traveling there. Because one could do both. At the same time.
Insecure Plugins Ding IE, Safari, Chrome, Opera
It simply prevents the browser from launching any plugin at all for any reason -- until you turn plugins back on. Web sites that do plugin detection are told that you don't have any.
Turning plugins off doesn't mean you're secure against Trojan-plugins, if there are such things. And no, it won't un-install malware or undo damage.
But it does mean your computer isn't automatically downloading and running every single annoying Flash ad that you'd otherwise bump into. That is, I think, the primary purpose of the feature: to make the web less annoying. But it surely goes some way toward shielding you from malicious Flash as well. If you're hardly ever running Flash, you'll simply have fewer opportunities for Flash to do something bad.
It's not as convenient as the Flashblock add-on for Firefox, but in my experience it's more reliable.
I use this option frequently, so I've got it set up as a check-box on the Opera status bar.
The Beckoning Promise of Personal Fabrication
You're not wrong.
But consider one very narrow aspect of this make-it-yourself-with-a-fancy-machine trend that we've actually got some real-world experience with: photo-printing.
A photo-printing service can crank out reams of ultra-high-quality laser-printed photos with a gigantic, capital-intensive piece of equipment. Due to the economies of scale, the cost per print is actually very low.
A personal inkjet photo-printer is slow, balky, finicky and has a voracious appetite for expensive supplies. Yet people buy and use them anyway, because they print -- or reprint, if they don't like the first result -- right here, right now.
There seems to be plenty of room in the marketplace for both of these options.