Excel Sheet Formatting - Very Thick Borders OR Columns as Section Dividers

OBJECTIVE: I'm looking for a way to format a sheet to appear as if there is a very thick border between sections of content - thicker than the thickest option found when going to (Format Cells > Borders > Line Styles). I've attached a general example for reference.

BACKGROUND: Since the line options found under Format Cells I have been adding a column between the content sections then make the width .5 or 1 and fill it black. This works for the appearance, but it's not an efficient option for documents because then I can't just select an entire row to change the rows color without impacting my section divider column. I have tried locking the cells, but then I still can't select an entire row and change the fill. (Since the lock won't allow it)

QUESTION #1: Is there a way to lock cells that allows me to select locked cells and unlocked cells, but when I change the fill it only changes the unlocked cells? 

QUESTION #2: Is there a way to set thicker line styles?

If there is another method that I'm not thinking of, please share! Any and all help is appreciated!