I perfectly understand how you feel about things. I too am a type "A" personality, but in my case, it's to an anal degree! Is there such a thing as A+++++++++++++++!!!
There may be legal issues with you keeping Office 2007 or any other apps on the PC you purchased. I cannot state for sure, but it is almost certain that the licenses you now possess on the machine are not meant for single machines. However, there is also a chance that they are. If they are OEM licenses, then you may be free to use them even if you didn't get the disks with the machine... after all, you "purchased the machine". It would be like you bought a machine and lost the disks yourself. Therefore, you may be in a situation that you could borrow a copy of the software and apply the license numbers that are now resident on the machine. As stated though, the probabitlity of the licences being OEM is low, given the computer came from a University that would probably use multi-machine licenses.
Some, if not all, of the applications you'll be using for identifying your hardware, will also identify the license numbers of Windows, Office, and/or possibly other software. You could capture the numbers and investigate whether they are OEM or not. If they are OEM, then I really see no reason you can't use the licences as OEM license is granted for use on the machine the software is installed on. Since you are not changing the machine, the OEM license still applies. I have to throw a disclaimer in here though... you will be responsible for any legality issues. You knew that was coming right?
I can still help you try to identify the licenses though.
I also understand how you feel about being the sole Admin. However, there is no way I know of that the Admin can be changed without reinstalling. I'm sure you can chage the name that Windows will show for Admin, but that doesn't really change the account name... only what's displayed, and during a safe mode boot, you would still see UVU. However, considering you would only use the UVU account for possibly troubleshooting in Safe Mode, and you can change the password to something you want to use, you might just consider keeping the machine as is. Any account you create can also have full Admin rights, so if you create an account for yourself and password protect it, you will still have full control of the machine. If you use TweakUI, you can hide the UVU account so you wouldn't ever have to see it except during a Safe mode bootup. If you don't understand how to use TweakUI, I can help you with that too.
As for the other user accounts, you can always just delete them in Control Panel User accounts applet and also delete their folders. Yah, I too dislike McAfee (andy Norton apps too!). I personally use AVG 7.5 as my antivirus but will have to go to version 8 sooner or later. I've tried Avast before so maybe I'll try it again when the time comes.
In any case, install the programs to capture the information. Any hardware listed in Device manager will be required. Also, indentifying the motherboard is important to find out whether it's Intel or other so we can find out what chipset driver you'll need. I know for sure that Aida32 will capture the actual licenses... not just the hash numbers. Try several programs until you're satisfied you have all the pertinant information. I'll probably ask you to list the hardware here to make sure we have it covered. If you need help let me know.
Personally, if it were my machine, I would rather format and reinstall. I don't like machines I "feel" I don't have full control over. I guess the only thing left for you to consider is whether the applications currently on the machine is worth the aggravation of keeping them with the tradeoff of knowing you are not the sole Admin. Investigate the licenses and go from there.