Looks nice. I would consider a 6' tanning ledge just to give more swimming room, that tanning ledge is huge. You could make the spa and tanning ledge on the same end with the spa in the corner as JJ indicated, but how you have it is nice also. It's all your preference and if you like it go for it.
Agree with JJ on robot, however with that large of a tanning ledge, you are going to be doing a lot of sweeping no matter what.
If you keep that large of tanning ledge, or any tanning ledge for that matter, and the color you have shown, I would recommend the Puerto Rico blend for the pebble. If you haven't chosen your plaster contractor, I can suggest one that will add the glass beads at no extra cost, it's just no longer "Stonescapes".
2nd the Intellicenter.
If you have a lot of wind, make sure and get the self lighting fire bowls. We ended up scratching ours out of the build due to the amount of wind we get.
Make sure you can adjust the bubblers. I like ours, just wish we could turn them down a little.
You will love having VSF on both pool main and feature. Make sure the Mastertemp is the 400k btu one.
Not sure having the return locations right next to the skimmer is a good idea, but will let someone else chime in on that. Our skimmers are on the end, and I find the wind usually determines more than the return on where things end up. Would suggest thinking about wind patterns for skimmer locations.
Hope this helps! Have fun!