Hello John, and welcome to WikiTree! I suspect the vast majority of us have some sort of living relative and I've really had no issues with protecting their privacy. Living records are locked down to only those you choose to share them with (well, besides the couple of Admins, but that's going to be that way with any site). If you decide you wanted help setting up a living relative and wanted to trust someone, you could add them to the trusted list for the assist, then remove them if you chose to do so. So the control of any living information is all in your hands.
As far as recently deceased goes, you can't keep them completely blocked like the living, but you can restrict them pretty heavily so that about the only thing people can see would be their name, birth decade, and death decade. At the near highest restriction, it doesn't allow you to see much. That's more for others so that they don't create duplicates. We're a Global Tree and our goal is one profile per person on the site. If duplicates are made - no worries - they can be merged together.
Hope some of that helps - enjoy getting your tree underway here at WikiTree!