If a Bot is to Add Control, and there is an uncontrolled space AND a space where enemy units are present, but the number of units to be added will change control, would the bot have preference over either of these places...assuming they are of the same population.
No. As long as its own side ends up having more Control than it had before the current action, the bot is satisfied.
I agree that if the bot were to Change Most Control... then it would select the enemy controlled space and flip it...
I don't! Unlike Opposition/Support, Control isn't tracked in levels; "change most Control" simply means "change the Control status of the largest amount of Population from whatever it currently is into something else". (This has been clarified in the errata, BTW.)