Wow. Seriously, that is a good custom deck. I really dig the crayon look. I love that you upgraded/customized the standard courts. I would like to see full custom courts, but I do understand that for a deck that is intended for magic, this is the maximum you wanna go.
One thing that I would change, the colours of the suits should be easier to distinguish. I don't really have a problem with the choosen colours, but I can see people confusing them easily.
The whimsical back design is exactly how I like it, but maybe some folks will find it too busy.
Overall, if the price is right, I would definetly add this to my collection. I'm curious how the tuckbox will look.