Hi!
The steep learning curve of the XP has been discussed here before. I see the problem; these synths take a lot of time to really master, and even then there will be lots of functions that you have never used.
The advice I would give is to try to understand what I would call the LOGIC of the XP.
All PCM synths like the XP are basically the same. If you know how they work and what they actually do, it all gets much clearer, and you can even move from one synth to another relatively easy.
The problem is that many XP-users do not know of the basics of the instrument. One such example is the question in the start of this thread, about patches, waveforms, what is stored where, what consumes processing power. If you know how all this works, you will notice that it works in the same way in a Technics, Yamaha or Korg as it does in your Roland. And Tracey, I am not trying to make fun of you! Really!
So, my advice is to try to figure out the fundamental basics of the instrument, in addition to reading the manual and trying to create music. It worked well for me..
I have focused on understanding how the synth actually works instead of trying to memorize procedures and stepping through them like a checklist.
Just my opinions!
Stig