What services?
Data Recovery, and many other things. (you asked)

Where?
Minneapolis, Minnesota (data recovery services headquarters)

What is their name?
Kroll Ontrack http://www.krollontrack.com/

Google for the columbia disaster for an example of their work.

Here in Minneapolis Minnesota, the data recovery services Kroll Ontrack http://www.krollontrack.com/ are headquartered here. Their company does a lot of different things other then data recovery, but their data recovery services DO cost an assload of money.

When the shuttle columbia burned up, NASA recovered some 6gb or something seagate drives and they brought them to kroll and were able to pull a 90+% recovery rate off those drives. I don't have a source on this, but im sure a simple google search would find it.

However the above wasn't data that was overwritten, just burned and partially melted. Also as for your questions, it widely depends on a multitude of factors. Sometimes you can pull most all of it, and sometimes you just can't.

they could find more vulnerabilities in a windows install.

that is truly amazing. Thats like one message every 12.5 seconds, im surprised their phones didn't crash or the keys didn't wear out, break or the battery died... They truly have a lot of time on their hands.

But I wouldn't want to go head first down a rail...

Bingo, if this is ever implemented, then there would be a mass-outcry no doubt that its so inconvenient for them.

Everyone wants everything in this world, but the question is: Can we trust them with it all?

you should do this regardless of any security. I ALWAYS check programs (if program is small enough I even scan the code) before running it, thats what responsible network administrators do. If you are not checking programs out, then I would not be surprised if you were or are attacked.

Also I would like to thank you for using linux, people like you and me are way ahead of the rest of the population still plagued with problems such as the one we are discussing. (not that linux is bulletproof, but it is close). The system I am proposing is close to the linux approach. Only that the admin cannot do daily user tasks in that account. In linux root can do those tasks. In my approach, they cannot.

Please read above mentioned points, that topic has already been covered.

To save time ill summarize. Malware authors are going to set that. Its expected, and if an admin executes the bad program without checking it out. You now point I hope...

Also I should explain the last point. Command prompt couldn't be blocked. I need it as an admin. Administrators should always check foreign scripts before executing them. Its not that hard to get the source code to a batch file or VBscript or (insert favorite cmd language here). Admins can always download using their standard accounts and switch users to execute it. Its more inconvenient but it takes almost as long to display and read a UAC prompt anyways. A switch user takes what 10 seconds. Thats a really long time.