Eder, this was great work and I would say that you have addressed issues that myself and fellow designers have pointed out. Here are some additional thoughts about some of your points.
In some cases, the brand is the product experience. The current state of Sketch doesn’t have much of a brand to me, outside of IA, because of the usage of Apple UI components. “Identity” might be another word to use. However, if they improved the different elements with color, style, space, etc. I could see that as branding.
The addition in Block 1 of the vertical lines is a great touch especially for commonly large documents. This reminds me of IDEs I have seen in recent years for code folding. Not sure if you borrowed that from those types of tools.
Having a common plugin location similar to the Craft plugin is helpful. It would be a consistent location to manage all plugins. The tooltips idea would be really helpful, especially for new users. I would argue one tiny detail in the implementation of the Craft plugin. Regarding the full vertical ribbon used to show (now 5) buttons, it takes up valuable space. Many times, I have found myself wishing that ribbon ended after the final button. It covers screens that I am working on, I have to move artboards and the canvas to accommodate it, and it’s worse when you go into Presentation Mode (⌘ + .). Actually, I am not sure why the plugin even shows in that view.
Kudos on the Block 4 major improvements. It makes better use of space and contextual logic.
Overall, if Sketch released a version similar to what you have shown, I would jump all over it. Nice work!