Woopdedo. Unless you have a really shrimpy monitor, I don't see that as an issue. It's virtually full screen with the exception of a small bar at the top and bottom. Besides, there are other ways to view them full screen.
what is ok for you, does not necessary be ok for everyone else. i guess you have a large monitor, but imagine you have a mac book and this totally large "edit bar" on the right is there all the way... it is inacceptable that you are FORCED that it is there!
also the bar on the top and on the bottom: it distracts the view! when you choose photos, you have to be able to see the photo only. you need to get a clear impression of the photo, not of the border around with color information of other photos that are stacked in a small bar on the bottom.
it is actually OK that apple supplies you with the functions, and it is ok that they want you to see them as default. but it is not ok that you are FORCED to keep it that way. it is as if you buy a lamp at ikea and you can not switch it off, simply because ikea says: "no on-off switch on the lamp - we like it that way!".