I think I found part of what I was looking for.
I was worried that I had messed things up by already having the grid layout module, then installing Cherry Zen over it- but I assume the Cherry Zen template file overides the default template files? I found this thread regarding the column grid layout I was asking about- it offers an update (Pro) that corrects the issue I was having: http://zen-cart.com/forum/showthread...288#post495288. So that fixed the font centering issue & gridlines.

I have learned quite a bit by your detailed instructions with your template files as well as this thread - thank you.
Diana