Google-sheets – How to make the “Text contains” evaluate any word written in the cell

Try:

=COUNTIFS('Form Responses 1'!$B:$B,Sheet2!$A2,'Form Responses 1'!$C:$C,"*"&Sheet2!B$1&"*")

(One fewer $.)

The Sheet2! are not required.

=ARRAYFORMULA(OR(isblank({K2,P2,Q2,R2,S2,T2,U2,V2,W2,X2,Y2,Z2,AB2,AF2})))

ISBLANK() will check if each cell within the provided array is blank.

OR() compacts all the results into a single Boolean value. Without it the function will still check every cell you listed but will only change the formatting based on whether or not the first cell, K2, is empty.

ARRAYFORMULA() is necessary in order to allow ISBLANK() to take an array as a parameter. It prefers to work with a single cell otherwise.