I don't think Nintendo would be all that opposed to allowing a fan to write and get paid for a Zelda game. If they can clearly see that the material is very good and they got a cut of the profits, why would they oppose it? More money for them at the end of the day right? Money talks folks especially large amounts of money - you'd be surprised what it can do.
In fact, I wouldn't be too surprised if Nintendo started ZC in the first place. That's right Phantom Menace was an undercover Nintendo programmer and Nintendo started all of this so they could gain insights into what their fanbase thought was "good" Zelda. Fans will only devote their time to making a Zelda game they thought was "good" so by looking at their work they gain a wonderful insight and all for free. That way whenever they made new official Zelda games they would know with 99% certainty that it will sell well with their fanbase. They'd also get access to new and creative ideas which their developers might otherwise not have thought up of. It makes sense if you look at it from a business perspective.
There's a big problem with selling games on Steam. Who's going to pay you whilst you make your quest? Making a "flagship" quest like IoR, Hero of Dreams and Lost Isle is no small feat and will take up a lot of your time which you could have otherwise spent working.
That is true of many Indie games. Peope put in the time aforehand, and see if there is a commercial market for them, thereafter.
I've known peope at two divisions of Nintendo who have played ZC quests. They know that it exists. That doesn't in any way protect it, though.
I should note that you do not need the Cassic Modue to play existing quests. Rather, it grans you the Z1 UI (file select), the first five standard quests, and the cassic tileset as a base. Other complete modules will contain their own base quests.
We are going to have contests to create those, similar to how we did that for 3rd, 4th, and 5th; except that these will start out as new 1st and 2nd quests, per module.
Try the Defaut and the other modules. Have a look at the format. See what you think of it. I need to update the title splash for Default: It's a placehoer, at present.
You can set your current module per-programme, in zc,cfg and zquest.cfg (2.55). I do not yet have a modue selection diaogue in either programme, or in ZCL, and I'm unsure how we that wi work for the player (load once the player is open), but the player does not mandate using a specific modue to function. Changing modules in ZQuest, while it is running, should be fine, though.
At present, there is a bug with quest icons, but I will sove that after I am done spending uncounted hours on 2,53.