I've been trying to organize my wishlist, and I was wondering, if I delete an entire category (let's say it has 100 items listed), will all of those 100 items cease to be on my wishlist? Or do I need to go through manually and delete each one and THEN delete the category?

When you delete a wishlist category, the items that were in it are transferred to the default main category. So yes, if you want those items removed from your wishlist, you have to do it manually.

I see! I wondered if that might be the case. Thank you! c: