*Do more on your high intensity days.
*Add some plyos to your high intensity days, this can substitute for weights in the short term.
*Move your calisthenic exercises to your easy days.
*Harder runs require longer rest. If the intensity is above 90% you'll generally want to take almost complete recovery. For acceleration development I use 1' / 10m run as a good general guideline.
*Increase the volume of running on your easy days.
*Active recovery can be anything- swimming, biking, etc that doesn't get you overly tired or sore.
*Stairs can be used both high or low intensity depending on your objective.