Thanks again, everyone. Special thanks, V8guitar--your input was exactly what I needed to hear. But everyone's input has really opened my eyes.
Using all this feedback, I just sat down for about three hours and put together a suite of performances that I'll toggle between for a particular song I'm now working on. In case folks are interested (e.g. if you're like me and looking for ideas on using the kemper)...
I put together 4 performances, each based on profiles of a single amp. Two of the performances are meant for "lead" playing and two are for more "rhythm" work. The two lead performances started with profiles featuring high-ish gain. The rhythm performances used a single profile with very low gain. Aside from the differences in starting profiles, each performance varies in terms of how the profiles are parameterized, as well as differing in what effects sit on top of the profile.
After all the helpful comments here, I felt pretty in command of what I was doing in this process. I'm sure there are better ways to go about this, but I finally feel like I'm getting below the surface of my kemper.
Thanks again!