For me personally, I'd revert the economic mechanism back to HotS, i.e. 6 workers to start and uniform amount of minerals at each patch. I just feel the economic tempo of HotS and WoL was more comfortable to me.
The other option I'm thinking of is to reduce the degree of unit clunking-up, making them more spread out during them game. This would kind of make AOEs less effective and game-ending and make fights look more grand. (But the balance probably would have to be completely redone though.)