...How do I remove the Anchor Seal from the area where I will be turning? I am assuming that it would put goo on a turning tool and make a mess...
I remove it with a bowl gouge. At however many RPMs feels comfortable.
In other words, don't worry about removing it, since the turning will do that for you. It won't gunk up the tools any more than the wood itself will. You're gonna have a mess any way you approach it. That's part of the fun.
With the flat part of the blank as the bottom of the bowl (which I think is a good call, by the way), you'll have the choice of making a bowl with a natural edge along the rim, or turn it down to the point where the rim is level like a conventional bowl. My personal inclination would be to make a natural edge bowl, but it would be a challenging piece for me. It would be even
more challenging for you as a relatively new bowl turner. From the looks of the photos, I think you've got enough thickness in the blank to be able to get a decently deep conventional bowl, especially if you favor the thick end of the blank when you cut your initial round blank. My recommendation would be to go with a conventional bowl.
You can get Anchor Seal (or the house brand of wax-based green wood sealer) at Rockler or Woodcraft. I used to buy it by the quart or gallon (I don't remember for sure) at Rockler. Once I started dealing with a lot of green wood, I bought a 5-gallon bucket via mail order from Woodcraft. For a single piece, a quart should be more than enough.
When I'm working with green wood, I usually try to finish the rough turning in a single session. When I need to work on a piece in multiple sessions (like over the course of a couple nights), I just leave the piece on the lathe and tie a plastic grocery bag over it at the end of the session. (Be aware this can cause a bit of minor surface rust on your chuck jaws if the wood's real wet.) If you're going to leave it for a few days, then I'd suggest removing it from the chuck and slapping a coat of sealer on it when you're done working on it for the day. When you remove it from the chuck (to prevent rust), mark the piece so when you re-mount it, you can put each jaw back where it was originally. (You'll still probably have to re-true the piece after putting it back in the jaws, though. No biggie.)
Be calm. We have faith in you, young Grasshopper.