Lets get real about the most likely scenario with NS.

[DanneSandin]

I ahree with most of the OP;
It'll sell really well in Japan, but only OK else where (ending up around 30m-40m ball park)
Western 3rd party support will drop off eventually, in like 2 or 3 years, 4 years at the very latest since you'll have the PS4 pro 2/XBox Scorpio 2 (or simply the PS5/XB2) - unless Nintendo does something similar and makes a Switch 1.5 or a docking station that ADDS power, thus keeping up with the competition. Japanese devs will support it all through its run though.
Switch isn't a bad name, it explains what it does effectively.