In the same circumstances, loving Nintendo games and not having a Nintendo console since Gamecube I'd probably buy a s/hand wii u with all the best wii u and wii games I could get for the money. I'm just thinking of all the games you have missed out on. For the price of a Switch in the uk I could buy a new ps4 and s/hand wii u.
I understand your point about darkness and sometimes Nintendo games are just more appealing on certain levels so you certainly won't go wrong with a Switch. However the reality is you will have a fairly limited range of games to choose from and they won't be at the same performance level as ps4. I really think if you weren't that happy/impressed with ps3 then ps4 may not be the choice for you though. It's pretty much the same developers across both.
It sounds to me that you won't be buying a huge library of games and will be focusing on each game you buy quite extensively with a lot of time spent per title so in that regard the Switch is really good. You can spend 100s of hours in Zelda Breath of the wild and no doubt 100s when Mario Odyssey comes out. Then there is Mario Kart and I guess Smash Bros and Arms plus some other stuff. I can see you being quite satisfied with your Switch purchase and getting great value out of it and you'll be able to do that at home and take it with you.
