You don't need access to the old host to set up a redirect. If you are using windows server you would use iis 7 URL rewrite module 2. Or programing it into the code behind or routing engine. If you using another server type than you would need to create what ever master file that server looks for.
You wouldn't want your shopping cart pages indexed at all. They would be unique to each person.
If you meant your product pages than either duplicating the old URL or using a 301 permanent redirect to the new URL is the best practice.
Please tell me more about your edu back links. I have several link building clients that could benefit.
Coryon
You should always try to build your own sites. Using other people's databases and logic gets you into situations where you have no control.
I know little about Linux but when you redirect to the home page your should log the referring URL so you can make a 301 redirect for that specific URL. Are you using 301 or 302 to redirect to the home page?
http://www.seomoz.org/learn-seo/redirection
I redirect for an honest reason is not a bad thing. Matt Cuts knows more than anyone about Google and SEO. He has covered 301 when they are right and wrong. 301 redirects are used for many reasons. Good ones are fixing caps issues and adding WWW or removing it. They also help for adding trailing slashes.
They are there for a reason. If you need to move a site and to get people to the correct page.
People who think they are experts used to use then to avoid losing page rank so Google takes off a small percentage when you do it.
Doing nothing is stupid and getting fake linkbacks is worse. Be honest and write good content. Consider building your own site so you control every aspect.
If you are still having issues Google will likely be looking at you in a negative light because they are being set every where.
If page A matches page B and you do a 301 from A to B why would Google hate you? If your page B is nit even close Google is going to think you are tricking people and are going to knock you down.
You need to take care to redirect everypage to the correct new page. Or make sure that you are using the same URL as you were before.
This backlinking is good after. But you need to get your site straight first. If you don't let Google know you moved the page then you will lose everything and if you move it with a 301 and the referring page is not similar to the new page Google is going to wounded why you did it.