Is there any way I can change the paints influence the movement of the model? This seems absolutely ridiculous. I’ve set my brush to subtract, size and weight to max and gone all over the model, nothing should be making the model move this much.
I’m sure I’ve come back to blender on 6 different times now, made a model, rigged it up then come across this issue and completely given up. It’s infuriating.
Take a look at your vertex groups, where you can select which bone group to work on, including selecting all vertices assigned to it and deleting all of the weights associated with it. When I have created a mess I occasionally unparent the mesh, delete the vertex groups, and start over. This data corrupts easily.
(Sorry if you know this already: the four areas you need to have open while in weight paint mode are 3D view, Tools panel - the weight paint brushes, Properties or ‘n’ panel for when you need to work on a single vertex, and Properties editor - the tab with the triangle icon - I think it’s called Object Data - vertex groups.
Just watch this video, I know its 28 minutes long and the title says rigify but really its just a half hour explanation of all the idiosyncrasies with Blender’s weightpainting. I am pretty certain you will find the answer to your question in that video.