SD2 for me was very easy to use and learn. I am still learning tricks as I go, but I stopped using SD2 with the standalone Solo program that Toontrack offers and started using it as a VST through GarageBand on my MacBook Pro. The sounds were great right out of the box, I do have the Latin Percussion add-on and I am very happy with it. I use the congas layered with shakers all of the time, I do that through the MIDI Node function within SD2. I don't use the crossfade function on the Zendrum at all, unless I am going to use a module like my TD-6V, then I need to use the crossfade function. As I understand, since you are getting the Z4 chip, you could use the Zenedit program and setup your crossfades within it, then import the settings into your ZX for a really great effect. I am going down to Atlanta the first week of January and another Zendrummer, Dr. Shark, has the Zenedit program and we are going to really see what we can do with it since I am upgrading to the Z4 at the time. Sounds like you have the plan down, I found that there is no right or wrong way to play the Zendrum, just your way. Everyone is different and has different styles of playing. I mainly use my FC-300 for volume control now, I can use it to control sequences if I hook up my TD-6 or a MIDI keyboard into the mix, but I am not that far yet, one day.
FYI----Toontrack is offering 50% most software until December 31st. You may want to check that out, SD2 comes with the Avatar Kit, which is great, but they have so many other kits that are just as great. When you buy SD2, it comes with disks for all of the kits availalble, you can load them all on but cannot access the add ons until you go online and buy the kit, it gives you an access code to type in and then you are good to go.
Welcome to the tribe!!
P.S. I live in St. Louis, so if you are ever in the area, let me know and we can get together.