(1) Third party support is not specific enough. Games like Call of Duty and Grand Theft Auto would have only marginally increased Wii U sales. Nintendo needs third party exclusives. Level-5 is the perfect example of a third party developer that directly impacts sales. Even so, I firmly believe that third party support is not essential to Nintendo's success.
(2) Backwards compatibility does not always come with restricted hardware. Backwards compatibility is essential and Nintendo needs to adopt a method similar to Microsoft and the Xbox One for their future console.
(3) This is the most important point. Nintendo needs to reign in development / release schedules. Releases should not be months apart for different regions and important releases (Zelda) should not be delayed months or years. Nintendo had a golden opportunity to take advantage of their holiday boost with the release of a core title, but they failed to capitalize.
(4) Games like Animal Crossing: amiibo Festival and Mario Tennis: Ultra Smash are always going to be developed. Look at any previous Nintendo home console and you'll find budget titles like these placed between major releases. I have a hunch that most people criticizing these games have never played them. They're not terrible. You're not going to be as invested in these titles as a game like Xenoblade Chronicles X or Super Mario 3D World, but they're a nice change of pace while we're waiting for higher budget games like Star Fox Zero and Zelda.
(5) I don't think visuals make much of a difference. Besides a few instances, like some of the textures in Xenoblade Chronicles X, I haven't really been bugged by graphics. I don't see the harm in increasing resolutions, though.
(6) Do you want a more powerful console? Expect a higher entry price point.
(7) amiibo should be an alternative to downloading DLC. The Toad amiibo is a great example - it unlocks another feature in every level of Captain Toad's Treasure Tracker. However, that same feature should be available for a price without the Toad amiibo.
(8) Mario Kart 8 DLC was great, but Super Smash had too much and it was too expensive. I hope Nintendo does not adopt the Super Smash DLC method for future titles.