And the micro advantage is not all that relevant since APM and latency restrictions can be imposed on the AI to force them to play under conditions comparable to human players.
Depends on whether or not the AI can see through the fog of war. In some RTS the "insane" level AI has full knowledge of the map. But yes, if it has limited info, like human players, the strategy is much different and much harder for an AI to intuit compared to chess or Go. Unless the winning strategy in the game allows for constant scouting, but is unlikely due to the waste of resources on that unit