The issue with the CCR shortcut is that after the install it reports as Blank in CCR and in Preferences->Advanced->Shortcuts - IMO it should be reporting None.
If I set it to None in Custom, it reports as None, of I set to something (e.g. Alt+F2) it's fine, reports as such and it works…
The Count Pages and Modify EPUB plugins don't have default shortcuts and they report as None when they're installed, viz:
I installed Count Pages and Modify Epub together, i.e. no restart after CP, History only shows the installation of Modify Epub.
Whilst perusing the shortcuts list I was reminded of two default shortcuts that clash with long standing Windows shortcuts
Alt+Esc - Clear the additional restriction. Windows uses it to switch between windows in the order that they were first opened… and it takes precedence.
Ctrl+Esc - Clear the Virtual Library. Windows uses it to pop the Start Menu, and again it takes precedence.
IIRC those key sequences were also significant on various Unixy OSs.
BR