This is a good question - non-pharmacist and non-MD here. First, prescription covers the whole realm of "orderable" services - not just pharmacology. So if your ordering your also ordering (aka prescribing) non-pharmacological interventions as well. Also, PharmD's education would have to be adjusted to incorporate training such as physical exam skills, if the end goal is to be independent practitioners.
That being said, I'm a huge proponent at getting pharmacists outside of the pharmacy and at the bedside. My background is in cardiac surgery and critical care nursing - PharmDs are an indispensible resource and essential to the critical care team. I agree that your statement has merit and there are indeed specialities that would tremendously benefit from having a pharmacist provider. However, the support of pharmacists having prescriptive authority raises some questions regarding checks and balances (i.e. Writing orders and being able to access drugs immediately) and the possibility that some pharmacists might not want contact with patients directly. I know this sounds callous, but some pharmacy professionals I know personally prefer to maintain an arms length distance and be adverse to patient contact. They like hanging out at the pharmacy!
Medical practice would have to be legislated, which is possible in some states. However that also is a challenge, there have been political battles in state legislatures between medicine and nursing organizations to obtain prescriptive authority. So you'll have to consider that perspective as well.
I'd get involved in your state's and national pharmacy society. For my part, I'll ask a few of my pharmacy-counterparts here at UCSF.