Thinking about buying just dance 2026 for Nintendo Switch 2

I only played just dance briefly in the Wii and I'm thinking about buying the 2026 one for the switch, mainly to move more and have some fun in the process, but I have a few questions about the game and I hope you guys can help me out.

1. How accurate are the joy cons to detect the actual step? Ever since I played the game in the Wii I always thought that you could just do the hand gesture while sitting down and it would detect the movement as accurate. Not to "cheat" or anything since I understand the fun of the game is to actually try to do the choreography, but just curious.

2. Does the scoring accuracy change if I use the camera? I guess I would have to buy the Nintendo's camera? I saw in another post that apparently I can use my phone as a camera? Is this true for Nintendo or only other consoles, also does it work with both android and iOS or only iOS? If I use the camera do I still need to hold the joy con? I read in another post here that the iphone camera only works for one player, will the Nintendo camera work for all the players?

3. If I buy the just dance + subscription I get all the songs from previous games? I find contradicting information about this. My understanding is that I get some songs from the old games but the "base" songs from the old games are not available right?