I used to find the left toolbar very useful, and now I barely use it as a Tools Bar. But I understand it is important for new users. So why not have both? In my proposal, the Tools Bar could be hidden / unhidden by clicking a discrete arrow. The T Bar could return alongside it.
A lot of times we need the tool system and the Properties panel opened at the same time, so both shouldn’t be in the same area.
On the Top Bar, users should be able to choose when it will show based on the workspaces they are currently using. This could be done with simple toggles on the menu.
Both are simple fixes and I think they could improve our workflow a lot.
Hope you like it!