Search for Arrival.TimeBetweenArrivals in standard.sam then replace the number to one to get a lot vistors at a very fast speed.

Also search for Costs.QueueCell then change the number to one feel free to edit the other prices to one if desired.

Search for Region effects and you would see region effects and there Radius, Happiness, Illness, Hunger, Security, Attraction numbers they can go from -10 to 10. The higher the number the greater the effect it would cause.
While numbers zero and below would reverse the effect. Having the digit ten inserted where the digit for hunger would cause visitors to never be hungry.