nerd, a lot of really good advice here...wish we lived a little closer, I'd come over and give you some throwing lessons, but you are doing great.
What Joseph said about squeezing the clay at first is also something you should work on, when everything is very thick the clay can be shoved around a lot...most important is to keep everything centered, centered, centered.
Also I was looking over a picture of the tools you throw with, you have a really nice large curved wood rib... you also would find the rib that is about the same size, but has one side flat very helpful. When I'm throwing tall cylinders and as things can get a little out of whack after a couple of pulls, slow the wheel speed, use the flat side of the rib on the outside of the cylinder starting at the bottom and with very careful gentile pressure use a finger or three on the inside of the cylinder against the wood rib. Now, slowly and evenly raise the rib and your fingers to the top of the cylinder. This may take several passes to bring everything back straight and you will need to pay attention to the angle of the wood rid so you don't catch and have it stick to the cylinder when it is very thin.
A heat gun is a wonderful tool and opens up new avenues also, I use mine a lot.