You don't. Windows 7 E is a seperate product which will be sold only in Europe (and South Korea I think) and it will have a separate ISO (Checksums for that have been posted, so when they leak, we will be able to verify).
It's because I live in the UK and I would have the E version, but nevermind. I will use Firefox instead though.
Windows Seven E or not, it's the same result finally, because it'll install ie8 the first time you'll be using windows update.
No. You CAN install IE8 over windowsupdate, it doesn't automatically do so. Windowsupdate is no longer dependant on IE afterall.