I agree fully that this feels clumsy and unintuitive. I think it's also better to have all this type of "view" data (since some of it is anyway) stored in the library on a view scheme - by view scheme basis.
I think the best way to do it would be to add a Step #4, #5, and #6 to the Edit View Scheme dialog (since you've got the multiple step thing going in there anyway). They wouldn't need to be that big, because you could use Presets as the main way to apply settings, and hide the complex dialogs under buttons ... For example:
Step 4 would define the Columns and Step 5 would define Sorting. They wouldn't actually have the GUI to edit the individual columns, they would just be Combo-Box type things where you could select a Preset (just like the preset system you have in the "Customize View" dialogs). One for Columns and one for Sorting. Step 6 could handle the List Style settings and be pretty much as is (though maybe you could hide the thumbnail options under a command button too).
Then you could hide the main "Define Preset" dialogs, either as a choice inside those Combo-boxes or a command button inside the Step's "frame". It wouldn't even be that hard to make the changes, since you would just be using pieces of the existing UI and associating it with the View Schemes explicitly. It would add some complexity to the Edit View Scheme dialog, but not so much, and would keep the general layout in that window (which I think is functional and fine).
As far as renaming "View Schemes" I think there is no need, and it will only serve to confuse your v9 and v10 users. Plus, for those of us (the silent majority?) who actually use the tree view, switching it to something column related could be confusing.