I like dealing with difficult customers too! I work a customer service clerk. That is my job to make sure that the customer leaves happy. If they don't I didn't do my job right. I am extrememly happy with my job. And I work really hard for it. I'm one of the younger crowd too. I don't spend hours off my job to learn about it. My job isn't a life or death situation. But if I can make a difference in the manner of how I service my customers. I will do what I have to make them happy. It's just part of them job IMO.
As for the substrate. I now know Eco is safe. Is aspen safe from mites too?