Hi and thanks for commenting!
Max 22 selected units is intentional for now, because of UI and performance restrictions. Will probably change this in the future though. :)
We are working on balancing the map further for the next update.
The lag spikes are outside of our control. What server did you connect to, where were you located, and what was your ping? If you disconnect often, the connection to the server might not be stable enough, because of slow internet speed, long distance etc., that can cause lots of packages to get lost.