You can try right clicking on a given file, then selecting Other... From the list. Pick the program you want, and be sure to tick off the box at the bottom about always using that program, though it sounds like you have deeper issues. Whether or not they can all be blamed on Lion I'm not so sure.
I know this has been discussed in the past, but since I've never, EVER had a problem with it, I didn't pay much attention.
My Mac is now opening all rtf and txt documents in Text Edit.Long ago, when I switched over to Bean (and something else before that) for text documents, I did the Get Info > Open With trick on a document, changed it to Bean, then clicked "Change all..."
It's worked fine for years, but now every time I log in or reboot, documents open in Text Edit. It's not just Text Edit either. I also prefer to use Movist to watch videos rather than Quicktime, which has become buggy.
Same deal; it lasts until I log out or reboot.
And another problem is when I open many of my apps, I get the warning: "You are opening the application "Bean.app" for the first time. Are you sure you want to open this application?" Sometimes I get, "Firefox was downloaded from the Internet. Are you sure you want to open it?"
These are applications I have been using for years.
I've Repaired Permissions and Rebuilt Launch Services repeatedly, but nothing works.
I hate Lion, nothing but trouble.

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