Meguiar's Ultimate Quik Detailer is the finest quick detailer on the market today - if you're looking to remove dust and fingerprints and leave behind a slick finish with incredible water repelling properties. But Meguiar's does not recommend it as a clay lubricant and I'm willing to bet it was the wrong choice to use with the Klasse products as a "surface prep". I would highly recommend using it as intended once you get your issues sorted with the spotting, but unfortunately that may require a reapplication of the AIO to strip things down. I will also add, however, that if you think you may not have let the SG dry long enough before removal then most likely you did not.

As for being confused about one product being wiped off immediately (AIO) and the other needing a drying time (SG), that's perfectly natural as the AIO is primarily a chemical cleaner and nothing extra is really gained by allowing it to dry. In fact, allowing to dry will result in you having one hell of a time trying to remove it. As a general rule you don't want to allow any cleaners or polishes to dry on the finish - do the work with them as instructed and remove. About the only exception is a cleaner wax, but that's a totally different animal. Almost all waxes and sealants require time to dry and bond to the surface before wiping off the dried excess. Failing to do so will usually result in streaking or difficulty in removal. P21S is one of the exceptions to this rule.

Lastly, if you are even concerned about putting scratches in your finish by simply waxing the car, you're either overly concerned or you're doing it wrong. A clean, soft foam applicator will not scratch the paint while applying wax, and the wax certainly won't either. Nor will a clean microfiber towel for removal, as long as you aren't scrubbing the wax off or repeatedly buffing the paint after removing the wax. There is nothing to be gained by repeated buffing of the area - once the wax is off, it's off. Move on.