Three problems on weight paint Good day. I have three problems. I'm trying to do everything according to the lessons, but ...

After using automatic weight, when I select a skeleton - go to pose mode - select bones - press shift and select a mesh - go to weight painting mode - with Ctrl click on the desired bone .... nothing happens. But (!) In the toolbar on the right, I see how the weight value changes, I assume that the bone is still selected (?)
My model is black. I read that when there is no weight for bone, the color should be blue, and black should be the color when no weight distribution has occurred. But I don’t know why the automatic weight distribution didn’t work properly and part of the model remained black.

3)Dotted line to the center of the world. My original model consists of separate meshes. So it's problematic for me to move it to the center (connect / disconnect meshes later), so I want to set it not to the center of the world. I applied all the transformations, but after the rig of my model was created, the dotted lines also extend to the center of the cylinder. As far as I understand, this can lead to some problems? Should the model always be in the center? How do I get around this? Are the dotted lines is a problem? What did I do:
-Unchecked the Lock Object Modes checkbox
-Apply all transformations
-I thought that &quot;2&quot; arose due to the fact that the colors in the settings of the bone color sets/3d viewport may differ, but everything seems to be in order there
-created a new file, but there are the same problems
I am attaching screenshots with my project and cylinders (similar problems), as well as a file blender with cylinders.
maybe some of my problems are related to the fact that I'm using the maya theme for blender (and most of the hotkeys have been reassigned), but I'm not sure
Sorry if my questions are stupid, this is my first rig. I'm trying to follow the tutorials, but they don't have these problems :C


https://drive.google.com/file/d/1owdkeFN4z3eGcCcNyZHmUitdQYp8bF62/view?usp=sharing
What do you mean when you say that when you're in Weight Paint mode, nothing happens? You need to be in Object mode, select the armature, Shift select the object, switch to Weight Paint mode, and Ctrl left click on the bone you want and you should see the weight.
You have black color instead of blue because you have enabled the Zero Weight option in the Viewport Overlays panel. It allows you to see real zero weight, because a very low weight will be displayed blue.

If you move some bones it may not work because you've selected the Bone vertex group in the Armature modifier, remove it if you want all your bones to work:

The black dotted line indicates the parentage between the object and the armature, it goes from the origin of your object to the origin of your armature, but these 2 origins are not centered. So select the armature and go to the header menu &gt; Object &gt; Set Origin &gt; Origin to Geometry, and select the object and right click &gt; Set Origin &gt; Origin to Geometry: