So since I did my last water change a few days ago, there have been bubbles (a lot) forming and staying at the surface. I don't think it is a problem. It just looks like the bubbles forming from the filter flow are sinking and then rising back up, but they stay on the surface and there are a ton of them. I took a picture so you could see a little better.
As you can see, there are tons of bubbles on the surface and around the edge of the top.
My answer to all of your first questions is, no, I did not use soap on anything in the tank so don't worry.
Let me also add that my tank has never done this before after water changes. The top of the water stays crystal clear/clean