Congrats Jim! I also set up my PJ system this year, and its soooo exciting....!
Here to share a couple of opinions/ideas for improvement, if only for later on.
I would experiment with pulling both speakers and sub away from boundaries some more. Experiment being the operative word, and of course always in balance with your aesthetical tastes.
Without looking up dimensional specs, and guesstimating how much space there is in the pics, I would personally opt for a vertical bookshelf speaker, with a stand on top of your AV stand, so that the tweeter is on the same horizontal plane as your mains' tweeters. The ideal soundstage.
By replacing the horizontal mtm center with vertical bookshelf, you will achieve ideal center speaker performance, without lobing issues. Then again, your seating does seem to be quite front and center. Regardless, even if you keep that speaker, Id still get a stand for it. And even if you don't get a stand, and are dead set on keeping it on AV stand, Id move the center up to reduce reflections, and angle it towards listener.
Finally, you have plenty of working space for acoustical treatments. My thoughts, but again congrats on a great dedicated room.