As far as I could tell, once we've started a new city with unlimited money off, we can't turn it on ingame for that city.

We can only enable it when starting a new city.

Can we have the option in game to turn on or off unlimited money and unlock all milestones?

Same with day and night cycle. The option to turn it on or off is only given when starting a new city, so if we start it with day and night cycle off then we can never see that city at night. We need a slider to choose the time of day ourselves like in the PC version and be able to choose the speed the cycle runs at or be able to pause it.