Can a power amp have too much power, risking damage to a speaker?

Doing some quick math here, your Mac and K'horns or LaScalas should hit peaks of over 130 decibels in your room. Should be plenty of dynamic range available on demand.

agree... with your math😁. And will not even approach 130db in our theater. 

About 30 years ago a dealer (who shall remain nameless) in Philadelphia told me that basically, "Too much clean power has never hurt a speaker."  He told me a lot of other things that I suspect would get pushed back on here.

JBL warns about loud levels. See JBL studio monitor technical manual here last page caution section SPL!

Mike