Running vs. hiking - your husband is on target there. Unless you do a lot of hiking, it probably won't to much for your running. But running will help your hiking by giving you better cardiovascular endurance (good for powering up hills - if you did this often, like weekly, it probably WOULD help your running).
I was running long before I ever did step. The more I am running the easier I find step, cardiovascular-wise, although intervals are still intervals. You can certainly raise the step if needed, add power moves, and push yourself harder and still get a good workout - if you're not fumbling around, clueless, which is how I usually find myself during step routines ('cuz I don't to them often).
The "problem" I have is the more I run, the less I want to do anything else.