Thanks for the kind words!
I'd definitely like to encourage you to come up with your own AP and publish it!
There is no need to start with making custom cards if you feel like it's a huge time investment, especially since there is no official template for the new cards yet.
The even more modular way the new sets are made, it's actually much easier to make new custom content, since most story banes are generic and can be made into specific characters by setting them up in the story book.
The good people at Lone Shark did a terrific job at making the whole process of designing scenarios much easier, both for themselves as well as for all of us, and this removes a lot of reasons that custom cards were needed in the first place. Just use the scenario rules to modify the story banes for your needs and you should be good to go.
And don't feel pressured into releasing a whole AP all at once. You can start with a stand alone adventure and slowly expand the story until you're satisfied with its conclusion, regardless of the number of adventures it has at the end. The most important part is that you're enjoying yourself while working on the adventures.
I'd like to do another AP some day as well, but I'm currently way too busy to even play the game as much as I'd like to (then again, my core set hasn't even arrived at my local retailer, so it'll be a while until I get to enjoy it). In the meantime, I'm sure you can come up with something amazing, so I'm looking forward to it!