Good thoughtful inputs thanks for taking the time to review this!Totally personal preference, but I would use the double union only on the 3/4 inch and use the neverlubes on the 1.5" connections.
I would connect the aerator before the T.
I would replace the T with a single three way neverlube and eliminate having the two 1.5 ball valves.
I would raise the salt cell so the return from cell to the now 3 way valve only requires two 90s instead of 3.