Colour Profile Confusion`

[Cheeze439]

I've a few questions about colour profiles, but let me explain my setup first.

I use lightroom 2 and I know that lightroom itself uses ProPhoto RGB.

I also have my desktop in Windows 7 set to use a ProPhoto RGB profile.

Generally when I export from Lightroom I export to .tiff and with the ProPhoto RGB profile, to ensure I get an accurate export from what I am seeing in lightroom.

Now any thumbnails of these exports look like bright Adobe RGB images but when opened they appear as they did in lightroom. This isn't a big issue, just irritating.

I also use photoshop CS4.

So questions:

1) Am I doing all this correctly and the best way possible?
2) I publish to flickr, this site and occasionally for family to Facebook. Are my images appearing as I see them to everyone else or does it depend on their profiling setup?
3) I don't get them printed very often, but when I do, do I need to do anything to the profiling or is it embedded and picked up by whoever I get them printed with?

I'm finding it pretty confusing lol, I'd hate to think that although they look right to me they appear over saturated to other viewers.