Most "obstructed view" cabins generally have a prime view of a lifeboat, tender, or service boat. You probably won't see much scenery (perhaps small patches if you look at the right angle), but you will get daylight into the cabin.
In eight cruises, I have never seen anybody from Princess try to stop any passenger from bringing beverages aboard -- though I suspect that they might if the quantity is excessive. Aboard the newer vessels, all cabins have refrigerators so cooling your beverages will not be a problem.
Of course, if you're like most passengers, you probably will not spend very much time in your cabin....