When changing the rear brake pads on my 2016 Ram I couldn't get the new pads to slide on until I left off one of the stainless clips. Only the pad towards the piston was worn indicating the pads were not sliding on the rails. Will I be alright with only one stainless clip?

 

no. you need to clean the rust under the abutment clip. it will rust under the black paint...file it down untill the rust is gone. apply silicon brake lubricant to the caliper bracket where the clip seats. snap the clip into place, install the pads.
clean and lube the caliper pins.

you live in the rust belt...you should be cleaning the caliper bracket and lubing the pins yearly.