Yes, what you get on the screen is a typical media player interface, similar to MC front-end, you will get thumbnails of albums, movies etc and you can play them and they will play on your MC PC or in any zone that MC can see. It doesn't matter whether you're in Standard View or Theater View. It is a remote control for MC. There is a "remote touch pad" mode as I've indicated which is intended for Theater View mainly and allows you to control the cursor on-screen if you want to use the Theater View interface on the TV to browse instead of the iOS device. Please look at the JRemote site as indicated above, the screenshots will tell you all you need to know.
When you browse items, you can actually select whether you want to view as text or as thumbnails, however there is a bug at the moment which means it auto-reverts to a text listing once you've drilled down into a movie folder and see a list of movies - this is the correct behaviour for music albums as you would want to see a textual listing of individual tracks rather than cover art, but it's wrong for video. However you can manually switch back if you want.
No, it doesn't scroll Theater View if you scroll the list on the iOS device, it doesn't mirror what you see on the TV and is independant. But you can, as I've mentioned, use the remote touch-pad facility to browse on the TV rather than the screen of the iOs device, it's like having an IR remote control.