I think some of your suggestions are quite good, and I'd be surprised if others have not made them before.
I really like the current way to create a deck, where I can say, for example, I want one random Nocturne card, one random Renaissance card one random Event, one random card from Events or Projects, and the rest selected randomly from the available universe. Or, to do the same but also select a specific card that I want to practice with.
Having said that; it would be a great idea to set up a new kingdom and say, "Hey, pick randomly from one of your pre-created kingdoms and let's use that." Or, "Give us one of your Engine kingdoms. We used to kinda sorts have that at the old website, where players were given preselected kingdoms and could advance only after beating Lord Rat in that kingdom. But it would be a nice addition to have, say, 50 kingdoms created and saved and ready for players' use, divided into various categories...beginners especially would really benefit from this, and also mid-level players.
It would take some time to code this...but not too much time. And then, once done, a lot of people would use this feature, so I think it would be a productive use of time.
My two cents only, of course. :-)
p.s. Does the card dealer really favor higher rated players??? I'm not saying it's impossible that this happens...but it would really surprise me. Not sure what benefit this gives to the game itself. I would have thought that it was, indeed truly randomized in regards to players' skill levels, and that game results would be more due to, well, an individual player's skill level. (Of course, on a single game, luck enters much more into it...especially on kingdoms with certain card combinations.)