Jeff,
I doubt if you will be harmed by drilling into the siding. But if you do have concerns. Just wet it down before and during the drilling process. As for siding. In Virginia if you are going to vinyl side your house. You have two options. One, you can install the vinyl over the existing Asbestos siding or you can remove the Asbestos siding and dispose of it in a landfill that is licensed to accept Asbestos. People put to much emphasis in Asbestos. Just like Radon, When have you heard anything about it lately? Why was it removed from certain code books if it is imminent danger?