I don't know about how the free version is, but you can search in the list. If you select a name in the list, then start typing by last name it will search for you. I only learned about this feature when I asked the same question a couple of months ago.
So you can go to Katie Kirby by typing in 'Kirby, Katie'.
You can also have Roots Magic installed on two or three machines if you'd like. The flash drive is more for people not having a notebook. It's still nice as I take it to other people's home and such.