In the second pic, of the bottom of the bottom bracket, that clamp sure looks loose. Unless the clamp is loosened up. Must be.
Here's is what I would do. FWIW. That paint looks awfully slick. FB's suggestion is a good one. Rough up the connection a bit, with a grit inter-face left in.
But if it were me, I'd coat the inside of the clamp with clear Plasti-dip. After cleaning it. It takes up some space, seems to grip well on paint, and keeps the metal of the clamp from marring the paint. I've done it on most of my bikes. A small can of Plastidip can be a bit hard to find, but handy to have on hand. Have to let it dry thoroughly before use.