"Still I have troubles to catch the correct button. (up down is for me wrong)"
Me too, that's the biggest barrier to using multiple performances than the load time...in other words, the Kemper loads quicker than I think...says more about my brain than the Kemper though... 
.says more about my brain than the Kemper though.
Yep. To die young we are to old 
I don't envy your bands, must keep you on your toes...my brain couldn't handle that much variation
actually i love that variation. I get to use so many different sides of my guitar playing. And the connection when the band is doing something unusual with a song...... Had a gig a couple of weeks ago where I Saw Her Standing There came out as pure rockabilly. The look on the others faces when i started it with chicken picking and slap pack echo. And then how the band zoomed in with a “yeah that”s cool we’ll do that tonight” attitude.
An approach that works great for me when I don't know the songs I'm going to be playing is building "generic" performances based on the amp that was profiled. For example, I have a 5150 performance with several rigs from clean to heavy and a lead rig that has a boost and usually some delay, etc. I always follow the same convention where clean is slot 1 and lead is 5. This way if a song comes up that fits the 5150 sound I can select that performance and instantly have all the sounds I need for the song without having to think about it.
Add a couple of Marshall performances, some Fenders and whatever other amps you prefer and you can handle any song that comes up.
