Validation for non-blank entry and upper case values

Column E is the issue here.

1. If any of Cols A-D have an entry, force an entry in Col E.
2. Col E has validation for I or F, but Excel is permitting lower case i or f as well.
3. Col F and G are working OK.

Thanks for helping.

Forcing an entry into G
Excel can't force an entry into G except through VBA. IF you want them to make the entry into G before entering anything in A:D, that's possible with Data Validation but not the other way around. You could also use Conditional formatting to make the whole row Red until G is filled in (if there's something in A:D)

Capital I or F in E
You can go to Custom Data Validation and use this formula =OR(EXACT(E5,"F"), EXACT(E5,"I")) but you will lose your dropdown menu. Again, the way around that would be with VBA if you want.