I think the new gameplay styles can be made into an option (scorched earth and FOW in territory).
Could we also get a switch to disable the adjacency system please?
It can be removed via mod, but the mod has to touch so many things that a built-in toggle would be much preferable to avoid potential compatibility issues.
Unless I'm overlooking something, it's only the power plant and bureaucrat series of improvements that would require alternate bonuses for a no-adjacency game option.
(The pacing of the game is different without the megabonuses from adjacency clusters, but that's not a bad thing.)