- that there were NO changes in columns A-O
- U, Z, AF, AL, AR, AT must have intact formula.

Unlock cells you allow to be edited by users and protect the sheet to
prevent changes to non-locked cells!

- if column P was changed, then column Q must be populated

Insert a locked copy of column P (you may as well hide it), say column AZ!
Apply conditional formatting on column Q:
Formula: and(P1<AZ1,isblank(Q1)) and choose a color!


- if column AT is 10% or <-10% turn font RED. Red values must have comment
entered in column BN so highlight empty BN cells if AT is red.
Apply conditional formatting on both column AT and BN:
Formula: or(AT10.1,AT1<-0.1) and choose a color!

Regards,
Stefi