Thanks again for the feedback everyone, it's super appreciative!
I have made additional changes though the biggest changes I've made have been more of a personal design choice regarding the imagery itself. I've been thinking about how I could make the two halves of most of the cards appear to be more intertwined but haven't come up with anything that wouldn't require me to pretty much do the entirety of the image, at least none that don't look forced. I'll definitely have to keep it in mind though as I'd like to have all the artwork done within the next month or two.
On that note, below are some of the additional changes.
The tuck box (I got a template from Bicycle so the shape is different. I made the hexagonal pattern a little more prominent without overwhelming the image.
Hearts
Diamonds
Spades
Back of the card; added a bit to the negative space while hoping it doesn't end up looking too busy