Ass loop TY so much, I think I got it!!
but it's not very intuitive, it would be easier to do it manually as when we move her leg or an arm, u know. Those red dots appear...
Anyway, I feel that maybe I'm still missing "plugin" or something, bcz I don't get any buttock bones. :s
Yeah, so something I see quite frequently is people will construct a faux-IK rig by using folders/objects and NodeConstraints. Basically, they'll parent, say, multiple bust bones to a sphere or folder, and either hide the sphere using MaterialEditor or just keep it as a folder.
From here, they can just click on the parented folder/object on the workspace to show axis controls for it within 3D space. This is much more intuitive to manipulate, so it's just a matter of adjusting the position and creating keyframes in Timeline.
I'm sure you've seen loads of animations with a ton of nested folders named things like "HIPS | (some character)". Or perhaps just a bunch of crap named "New Folder" all nested 5 or 6 layers deep lol. This is the faux-IK rig, and manipulating these objects is what creates the motion. These are usually trickier to alter animations on however.
A particular set of bones may have 5 subfolders, but the maker put timeline data on every single one. This means no matter what you manipulate, it will always "reset" back to whatever Timeline has for it. Sometimes you can find an unused folder to make adjustments with, but more often than not you'll have to untick something from Timeline to manipulate it the way you might want.
But that's more or less how animations are created --- a fake IK rig is constructed using NodeConstraints, and you can just create keyframes and manipulate multiple bones in an "IK-like" fashion even though it's technically not even a real IK rig. What's interesting is you theoretically only have to make this rig once --- you can just make it in an empty scene with a default character, and then import that any time you wish to start creating an animation. It'll still require some tweaking with NodeConstraints and updating offsets when you swap characters, but I imagine this would be easier than making the rig from scratch every single time.
There are also different ways to create animations. HC for example just animates the IK rig directly, and only seems to do simple bone tweaks that are static (like shifting a body part into a position otherwise impossible). This is why you can quite easily swap characters in his scenes and the animation more or less stays the same, with maybe a few bone tweaks needed to keep things from clipping. Animations built with fake IK rigs need a ton of work despite being much more adjustable, because EVERY nodeconstraint needs to be updated for the new position data of that character.
Honestly, I think it'd be easier to spend a year taking a crash course in Blender than trying to learn the arcane coomer magic of KK Studio. I'd say I'm somewhat well versed in Blender and there's just tons of jank with how you have to do the same things in KK Studio, but it is impressive that there's a fully featured graph editor. It was never meant for animations of this complexity, but it does amaze me how far people are willing to go to make some good stuff.
As for "missing bones", at least half the bones are NOT named intuitively and seem to use romanized names. The buttcheeks in specific all contain "siri". If you select a character, right click the KKPE icon in the lower left corner, it should pop up the advanced window. If you click "bones", you can just search for what you want and it'll show you every bone with that word in it.
I will for sure work on a video to demonstrate making a basic animation, from making a janky rig to animating it. It'll take some time though.