1) I do prefer swapping them.
2) That depends on your goal. If you wish to have it swapped indefinitely, you can get a custom controller for the Filco (as well as many other keyboards). If you don't want to do that, can't, won't, etc., there is always software to reach your goal.
3) If it's an option, I like stepped. It helps finger positioning. Though I think it's more along the lines of being out of the norm for most people.