Anyone have any input? It is much appreciated.
To be frank, that routine is pretty bad for developing strength. It's right there in the beginning of the PDF. If you really want to get your bench up, if that's truly your goal, then you might want to take a hard look at where you are progression wise and move from there. GSLP or SS might suit you better. If you're more advanced than that, Texas Method or 5/3/1 could be up your ally.
I mean, your suggestion works (I'd add the incline), but it's just not an optimal program for that.
As for ab work, I like to do it on any lower body days. Just a few decline crunches, some hanging knee/leg raises, and dumbbell side bends work great. 2-3 sets of 10-15 twice a week should suffice.