Absolutely.

First, it won't come out in 2017. It'll come out in 2017.
Second, if this generation is anything like last generation, and it will be, the PS4 and XBO will last like 8 years. 2021 is then this generation will end at the absolute earliest. That's plenty of time for the NX to settle into the 8th generation, technicalities on generations aside. Nintendo isn't going to refer to the NX as their "9th gen platform." They're going to refer to it as their "current platform." Only crazy internet people care about what generation a system is apart of.
Third, there won't be a PS5 or XB2. They will be services by that point. No more consoles.

The console variant will likely be more powerful than the PS4 by an insignificant margin if only because of more modern tech, but they want to remain "affordable," so don't expect Nintendo to try and blow them out of the water.

I see NX being capable of 3-5 Tflops and XBO/PS4 of 7-15 TFLOPs. If at the lower end of that scale for each expect NX games and PS5/XBO games being quite identical except PS5/XBO will run said games at sub-4k resolutions and Wii U at 1080p resolutions. If the upper-end, expect there to be a difference, but not as large as Wii U and PS4/XBO.

Law of Diminishing Returns comes to mind.

One of the main problems is everyone has this stupid mindset that whatever Nintendo makes is deemed a kiddie product.

Absolutely not happening. Third parties were disappointed with the XBO/PS4 upon their release, performance-wise, while the PS3/360 were actually high-end hardware when they released. This generation will probably be closer to the sixth in length rather than the seventh. New XB/PS in 2019 at the latest (which would be six years.) I'm thinking Holiday 2018 would be more likely. 

If it comes out next year yes.
People upgrade their phone yearly, if nintendo can do a gamecube with their tech (more powerful, cheaper) they can make a profit and hold on till next gen to see where things stand

No, definitely not. Nintendo is in a bad place right now, and to attract customers they need to offer something compelling and cool. Perhaps they have a novel idea like Wii up their sleeves ; but barring that they will need to offer something technologically advanced to gain interest. With the significant advancement just unveiled with HBM and AMD's new chips, they have a rare opportunity to offer a product a full gen ahead of the market in about 2017. Assuming they're smart, of course (doubtful).

They for sure need to build a new console that is at least 5 times more powerful than the PS4Xbox One. Having one that was only slightly more powerful than the PS3 and Xbox 360 didn't work. This will hopefully put them on a more equal footing in the minds of third party developers and get more support.

Who cares if third parties were disappointed? Did they stop supporting those systems? Nope. Third parties are still supporting last gen. What can they do? Just stop making games 8th gen games until something new comes out? No, they'll deal with it and make games for the PS4/XBO until well after PS Now and XBL take over. And that won't happen until 2021.

Third parties have a lot of influence over Sony and MS. They can easily go into a hibernation mode (as Japanese developers had done last gen) and limit the growth of Sony and MS in the market. Also with a growing PC market and competitiveness of Sony and MS in terms of exclusives, one of the companies can try to win third parties over the other by releasing earlier. I have to say your prediction on this one is just not going to happen. 

Te problem Nintendo has they are still seen kiddie and therefore you cannot release at a price point like the competition. SO they are stuck in a hard place. If they want to make it 5x-10x better than PS4 in 2016 it will cost $$$. But at the same time if they make it too weak then it won't sell or get support.

They should make it modular to keep the launch cost down. So release it in 2016 with slightly better PS4 gpu specs but much better cpu. Then 3 years after 2016 release a new video card module and additional ram modules to stick in or replace the old. I am sure if they could negotiate a long contract with amd they could get a good deal.

Hell if alienware can create an external box for a gpu to boost their laptops why can't a console be modular?