For most programmers placeholders don't cut it, they need visuals to keep them occupied.
Unless the said programmer is a robot and doesn't care about that.
And how would a fan game make money, thats illegal.
Technically so is making a fan game to begin with. Most companies are too busy having sex and rolling around in their gigantic piles of money to care. But again, now you're asking people to create graphics which they technically don't need to for FREE. As a graphic artist myself, I'd definitely be turned off by a "Need graphic artist to make Hi-def versions of every Zelda sprite from Minish Cap because I don't want to have a 2x scaled version on screen." post, but that's just me. Not saying it's a bad idea, because if I stumbled across a hi def minish cap sheet, I'd !@#$% bricks!
As for mouse controls, that would be sorta cheap unless you're planning on a point and click game which is pretty much all a mouse can do. A Zelda game would be limited to 2 items at any given time IF you don't want to be able to engage in conversation, or unless you wanna utilize mouse3. The keyboard is the perfect "gamepad" imho. You have your up down left and right, plus essentially unlimited ammounts of other buttons. Not to mention it's easiest to map up/down/left/right to w,a,s,d and then have your other functions be on the numpad, or something... I dunno.
I hate sounding so negative, but it just feels like the whole "innovative" gameplay pitch again. Innovation isn't making link do a spinslash by spinning the mouse around him, it's making Link have to do a complex puzzle to even GET the spinslash!