Is getting a back up necessary if I don't care about wanting to save my gameplay files for Uncharted and Overwatch when I intend to buy a 2 TB Fire Cuda very soon? I just got a PS4 Slim a few days ago and only began to play those, so I wouldn't mind just starting over and reinstalling the digital versions of Overwatch and Titfall 2 that I bought off of PS+, and whatever download requirement the physical copy of Uncharted 4 requires. I haven't opened the game case for Bloodborne yet. Other than that, the only other content on the default 500GB I have installed are gameplay demos for Nier Automata and Gravity Rush 2.
Well you could just back up the save files to the ps+ cloud, and download them later without having to mess with anything else. It's up to you, and if your internet is fast enough i'd say to go that way.