More responses! And welcomed!
1) I am flying a C172
2) I think most of my problem comes from varying speed. Not to mention the little updraft at the end of the runway near the highway interchange. It is presently very hot (102 to 104 F) and you can feel the heat as you pass over the highway. This tends to throw the plane up several feet right on close final.
3) Spins? Unless you are crazy, like the aerobatic pilots and your plane is designed for it, spins are to be avoided at all times! Honestly, I plan on taking a few hours of aerobatics in order to learn how planes get into bad situations and how to get them out. There is a school nearby which uses a bi-plane for training. I know the drill for recovering from a spin and have been read up on it. I guess I am not so scared of them as I once was. I just feel like the wings will come off if I do get into a spin. In a plane designed for it I wouldn't worry so much. But when you read the POH and there are all the warnings about too many Gs you have it anchored in your brain as "don't do this or you will die."
4) I am not quite ready to change instructors. I like and trust my instructor. My nephew, a Black Hawk pilot, has told me I should find another instructor, preferably one with military experience like he had when he got his PPL. But he is also nuts and flies too close to the ground.
5) Spilling gin and tonic is tantamount to spilling beer, which is a crime in Texas. The trick is to finish it before it is in a situation where it can be spilled.