Hi ManualNeeded, welcome to Poweramp. I'm like you perhaps, in that I find manuals helpful and don't mind reading them. Also, I've only recently made it into the world of smart phones, so many of the things people say are "natural" I don't think of.
However, I enjoyed playing around with Poweramp, getting to know it and finding the different ways it can do things. I also found andrewilley very courteous and helpful. Some things I still find a little frustrating, but on the whole it's the best app I've tried. So for me, not having a manual hasn't been too much of a problem in the end.
But would a manual be the answer? For instance, it would be difficult to explain in words the different kind of touch needed to give a star rating to a track, swipe across to change the track or access the menu. I learned by letting my phone teach me. After I'd tried things enough, I had adapted to the app without knowing it. Using it tends to bypass the brain quite quickly. A manual might help in the first few hours, but it would take someone many, many hours of preparation, checking and keeping up to date.
Good luck, and don't be afraid to ask.