Fallen Enchantress does not use Steamworks, so if you don't want to use Steam, it's as simple as not buying it from Steam. It's even easier if you were an early WoM buyer, as you already have it direct from us!
If you pre-ordered and got the beta through Steam, I'd expect Steam should be able to figure out on its own whether it needs a full reinstall when that time comes.
What we, Steam beta tester users, are wondering, is:
Should we uninstall the beta version and then fully download the release?
OR does the release overwrite the beta, so no need unistalling? In this case, all factions/sovs created will be deleted too, or need a manual erasing?
I was about to create a post for Steam beta testers, but I will use this, as you can see, we are still confused. Please, make a post to keep us informed...