Thanks for the additional feedback

Called our vet today and will bring Levi in tomorrow for another u/a. It may sound odd, but I hope it's something medical as it seems that might be more readily treatable than a behavioral problem.

If he gets the all-clear from his u/a, we'll continue to clean the affected fabrics in the house, get a Feliway diffuser (we have the spray, but have heard the diffuser works much better) and consider amitriptyline.

We really want to do everything possible to have a happy household!

I'll follow-up as things progress...

BTW, Jen & Randi -- I talked to the vet about the crystal presence -- was advised that because our cat is so young (8 months), crystals are not likely causing him the urinary symptoms we are seeing; evidently, crystals take years to build into stones, which are the culprit of pain/spontaneous urination/etc. If you have different info or studies I can read indicating otherwise, please let me know!