Function to return MAX value for a range

Why not just?

=MAX(E2:CA2)

Actually, it looks like the formulas in E:CA are text results.... the formulas should not have numbers in quotes. i.e. =IF($**$2-D2>=30,"25","0") should be =IF($**$2-D2>=30,25,0)

You should fix them...

otherwise you need to coerce them to numbers with: =MAX(E2:CA2+0) confirmed with CTRL+SHIFT+ENTER not just ENTER

or =SUMPRODUCT(MAX(E2:CA2+0))

and copied down.