Hi,
A lot of people have done it before and with varying degrees of success. You really need to consider two jobs here. Firstly you as a clinician. Even if you were one of the top graduates you will still find that many things come in your door that you haven't seen before. How will you handle this without erroding the confidence of the person presenting to you? I've been in private practice for 7 years and still get things that I haven't seen before, but my experience allows me to instill confidence in the patient that we will find a solution..........which is usually then followed by a Q and A with other staff, and then some form of online investigation.
I think the peer support element is important, but doesn't have to come from someone at your work. When I started out I was part time private, part time public, and used senior staff at the hospital to sound out ideas. Most of the time I was on the right track but it helped to have that reassurance. If you have someone you know that has been out for a while you could ask them whether they would mentor you, and meet once a week, or fortnight just to give you some support.
PD is a challenge, but there are now a number of online resources which are fantastic (I won't give the free plug but I can give you one name if you like). They one we use at work has an extensive online video library broken into 20minute blocks covering beginner to advance skills...........obviously miss out on the hands on but a good starting point.

Secondly, you have to job of running a business. There are a lot of elements to this as someone else has elluded to, and from someone that is currently making the transition to businessman from clinician, it does take a different mindset, which unless you were truly remarkable IMO would be a lot to take on as a new grad, but again, many have done it before.

Rather than a stand alone you might look to a gym or medical centre, where even though you may not have other physio's, the "business" as such isn't yours, you just rent a room and worry about your rent and accounts.

How long have you been looking? Have you applied for jobs and been unsuccessful? If so you should seek feedback as to the reasons someone else got the job over you, and even talk to the people that interviewed you about your plans, (if there isn't a conflict re location/competitors).
My advice would be to continue looking for work with someone else, but if you do go it alone hopefully the above helps, and please, let me know if I can be of further assistance.

Good luck.

I just noted your location........Things might be quite tough in healthcare over there at present. This might not only make it hard for you to find work, but it may also put the pinch on a new start up business.

Good luck with your decision.

BB