Easy answers to your bad experience:
1.) Too thick and orange peely: You waited too long after mixing the 2 components. It was already hardening. Remember that as soon as you activated component 2, you will mix and shake the can for about 1,5 to 2 minutes maximum and then use the can until its dead empty during the following 5 minutes! If you paint something and then put it in the corner for 5 minutes and then pick it up to continue, its most likely already too late and not usable anymore.
Also, the nozzle that comes with the cans is the first that gets clogged if you stop the flow of the laquer for 3 minutes.
I use the following trick: Whenever I have to stop painting for some minutes, I remove the nozzle cap and put it in thinner - then pressure air it real quick and put it back on to continue.
Using 2k laquers is absolutely rewarding! Especially in the long run and when its completely dried out. Its MUCH harder and more durable and super recommended for bike or car wheel restorations. However! Your projects and your work-flow needs to be planned and precise. There is no time to fool around or dilly dally here and there in your workshop once you started painting. When you paint, you paint! Fast, precise and accurate and then stop! And let it dry most accurately as recommended!
2.) It was low gloss when cured: If a fresh laquer gets dull, you most likely used it in a too humid or a too cold environment. Or both! Never ever spray-paint under lets say 18-20 degrees Celsius.