So I did it. All by myself after almost resigning to a whole new water heater and plumber and oh what have I done.
Always good in those situations to take a break/walk/meal and think.
Pictures of the project:
I ended up taking a better look at the situation with light on my stomach and discerning that the valve was screwed into the heavy metal tank. The valve threading was made of a somewhat plastic cermamic. For a minute I thought there was another interface between the valve and the threaded hole, but it was just sediment/grime. I was able to take a flat screwdriver and hammer and chisel out the remaining valve. Be careful! Do not screw up the threads by chiseling them out with the metal screw driver. I have one small gouge. It would probably be better to use something a little less hard for the chiseling. Harder than the plastic but softer than the metal (I don't know what that would be). Thankfully it came out in 3 or 4 large pieces and the threads cleaned out fine!!!!!! Awesome. I was able to discern how much valve I had left in there with my finger.
I also heated up the area with a space heater and then a blow dryer. A heat gun would have also possibly been helpful. However, I didn't have one. I don't know how much the heat helped. A little bit. I was working on this pretty cold which was another mistake.
Teflon tapped the new all plastic :( valve and rotated it in there. Didn't tighten it like crazy. Maybe a quarter turn past hand with a wrench. No leaks. Holds pressure fine.
Ultimate upshot. The slow draining I was trying to fix was NOT the drain and this was all completely not needed. It was what seemed like pounds of heavy water sediment in the bottom of the tank. There is a pic in the link. So next step is to dissolve all of that crap. I was able to get alot out with my figer as I was messing around. A good way to maybe check for this is listen to the tank as it fills. I can hear the sediment swirling in there as it fills, yet upon emptying I never once! saw any sediment!
Hopefully this finds someone in a similar situation one day. You can do it. I gotta learn how to fit/solder pipe! I also now am gonna find what dissolves this crud the best and get rid of all that sediment. I saved a bunch for experiments.
I greatly appreciate the help everyone. In the end, it was what everyone suggested. I was just too busy fixing.