you sure can, charlie. There are 8 digital ports on an IoTiny. Any of those can be used for a bumper switch. Because the power (+) pin of the digital port is battery, it can't connect directly to the bumper switch. Instead, use the red power pin (+) from any ADC port instead. That provides regulated 3.3v power. Wire that 3.3 v to teh bumper switch, and to the IoTiny digital pin.

And for the IR sensor, you can use any of the 2 ADC ports for that. There's controls in ARC for the IR sensor including a cool radar scanner. Look here: https://synthiam.com/Products/Controls/Infrared-Distance