Its only risky for the brain dead, imo.
Just saw your posts at DW. This is a perfect example of how experience is put to one side in favour of opinion. From what you've posted here, I assumed you had some working knowledge of machine or hand polishing, but you don't. I'm sure you think I'm being a ***** for pointing this out, but this echoing of opinion without experience is how we go from never use a rotary > use one with caution and practice > can your sister do my Aston on Saturday? She can use my Makita.
The time and money issues don't really make much sense if you are now buying a PTG and consider the practice you'll need and how often you'll actually mop your car.
If you get good at it, you will have a new skill though so I understand the attraction, I used to wet polish granite.
DW is a great resource but it's changed massively and not coped with its growth very well. A new member doesn't get 10% of the opinions and knowledge you used to get 4-5 years ago and the whole DA vs Rotary thing has been done to death so many times, a lot cannot be bothered to comment anymore on it.
There is without a doubt a certain cachet in using a rotary over a DA, so I don't think you always get a balanced view.
Anyway, here's one I posted years ago, second car I ever machined polished (so a relative noob), did it as a favour and practice for myself. All DA, Optimum polish I think and took longer than a Pro with a rotary but I'd guess quicker than a beginner with one to get the same results:
I really hope your ST comes up nice, I'm sure it will. But please don't make assumptions about how thick people are if they damage the paint with a rotary. It really does happen to pros and keen, well-researched enthusiasts alike.