Swamp Coolers and Interior Humidity Levels

I am in Southeastern Arizona and am almost ready to start construction of a straw bale home. Almost because I ran into this question. Swamp coolers are used fairly extensively here due to the dry climate (most of the time) However, they can elevate humidity levels significantly, especially during the Monsoon season. I was considering a lime plaster on the outside, and an earthen plaster on the inside initially. AC is not an option due to home being off grid. Since it has a loft, I will be utilizing roof vent systems.

1.) What effect, if any, does a swamp cooler have on a strawbale wall system? and

2.) Would a lime plaster be warranted on the interior as well, or would an earthen plaster suffice?

Just trying to cover my bases now, as it is a lot easier to make changes on paper than on the actual project.

Thanks in advance guys

Tim