It sounds like you're just dealing with the usual consequences of using a cms - lots and lots of over-engineered code so that problems arise as soon as you make changes. Just work through the issues one by one.
Good to see you are finding solutions yourself, but do pause to read the posts made by others - as I said in my first post, use conditional comments to send css to ie only.
Rather than adding more and more controlling code (eg position) to fix the issues with the email and name, find out why they are behaving that way.
If line-height is a problem, adjust it. You can use the ie developer tool bar to see what it currently is, adjust until it looks right, and then make that change in the css.
Again, rather than trying to control everything by "making" the page show in ie8 mode, I'd suggest trying to find out why it is switching. One thing that will trigger a switch is recovering from errors - validate your code and see if that removes the issue.