>>2971279
Breathing in: Upper Torso 1 rotates 5~10 degrees to the front (minus) on x, Upper Torso 2 rotates backwards by the same amount + 2 degrees, shoulderPs move backward and down (Y rotation), the neck rolls back along with UT2 slightly, while the head reverses the combined rotation to maintain the original angle.
Breathing out and in: copy, delete, write, move forward by the desired interval (30+ frames for natural breathing), write, move again, write, move back, paste. Change the interpolation to an S-curve for all, optionally change the interpolation for the middle key. Congratulations, you now have a basic cycle. You can also spread out the keys.
https://video.twimg.com/amplify_video/1931280816232919040/vid/avc1/1280x720/OaXW7eO1dVbD2pGV.mp4?tag=14

Use MMM motion layers or clips if you need to combine it with another motion. Alternatively, you can incorporate フルオートブレスユニットv1.62 and use that.
For other motions, check out なんかモデルがダンスーる, ふちょお誕生日モーション, and maybe you can find something else in https://files.catbox.moe/fxmzx8.txt

>>2970759
It depends, but usually no.