I re-did them all and they still don't work in v.5.11 – but work fine still in v.5.10. So I don't think it's anything to do with the OS.
These are the ones I have:
shortcuts.jpg (117.73 KiB) Viewed 13021 times
But they may conflict with other OS's?? And it's just my personal choice of course.
Again, personally I don't use the Command line much any more, so I'd probably delete that if ⌃⌘C was better for something else. The Library mnemonic only really works in English (Library = Books = B). So perhaps ⌃⌘L would be better for the Library and have something else for Lock (perhaps ⌃⌘G so Lock and UnLock sort of go with Group and Ungroup??)