I think the 2.0 and 2.1 updates are pretty interesting! One thing I would be interested in is a better trading mechanic. In 2.0, one of my preferred strategies would be to, for most cities, set all "new workers" to be farmer/fisher, and then any excess workers would go towards trading.
What made that sort of experience semi-streamlined is that whenever a worker became available, it would be displayed in the "advisor" section, meaning I could go ahead and send the worker to trade with another city. (By the way, one thing I would also recommend is somehow highlighting which city is selected when a city is selected. Also, a minor bug I noticed in 2.0 was that whenever a worker became available and I had the advisor screen open, the advisor screen would not update. I would have to click away from the advisor tab and go back to it in order to update the available workers)
Another idea I've had is a sort of a way to see where traders are going, what cities have lots of incoming traders, etc. I'm still re-doing the tutorials for 2.1, but in 2.0 there were situations where one of my cities would be overwhelmed by foreign traders, and so it would spontaneously turn into one of their cities. I actually really like the mechanic, it makes things interesting, and maybe changing it would kill that, BUT I imagined it could be useful to have something like a "toggle-able overlay" that will display something like, the trade balance for various cities, etc.