a) Keep Nintendo Land until you at least play it. It isn't a Mini-game collection as much as it is a collection of 12 games. Would you shun a game package that put new smaller scale Pikmin, Zelda, Metroid, Donkey Kong, F-Zero, and a few more games together? That's basically what Nintendo Land is. 6 of the 12 games are purely single player only, and then 3 are competitive, and 3 are co-operative. Some of the multiplayer supporting ones also have single player modes. Anybody that doesn't really give Nintendo Land a chance because they write it off as a mini-game collection is a fool in my opinion. Just saying
b) All Wii controllers/peripherals will work except things related to the Gamecube BC. Whether the controllers will work for a specific Wii U game depends on that game supporting the Wii controllers or not. Games like Mario Kart and Smash Bros support the Wii remotes as controllers.
c) Wii BC works by emulating Wii completely. You basically switch to Wii Mode, get the Wii Interface, and can only use/do things the Wii was aware of. The graphics are upscaled from the Wii native 480p to 1080p, but not at the scale/quality of the PC based Dolphin emulator for Wii / Gamecube.
d) The Pro controller for the Wii U nor the Gamepad of the Wii U, nor anything else that didn't work with original Wii will work in Wii Mode. Well, the Gamepad can still be used for OffTV-Play, but you will have to use Wii controllers while just using Gamepad as a screen. They even have the Sensor bar included on the Gamepad so pointing-based games will work as well using nothing but the Gamepad as the "tv-screen".
