I am an active paramotor pilot. I often fly out of a local uncontrolled (700 AGL Class E) field. Of course, being as I'm also a professional pilot, I know all the rules and approaches and all that stuff. So when I fly there I do have (and use) an aviation radio.
A few observations about paramotors (some of these apply to other ultralights as well):
- They're considered ultralights, and therefore have to follow Part 103 like any other ultralight. Part 103 is pretty short, you can read it in about a minute.
- Since they're ultralights, there is no pilot certificate and no training is required by regulation. Most people get training (because it's kind of self-selecting for continued success) but not all. It is highly possible that someone who received no training won't have any idea about airspace or even what regulations apply to them. Yes, they are required to comply with Part 103, but that doesn't mean they even know it exists.
- Paramotors are REALLY slow, even by ultralight standards. They typically fly at around 20-25 mph in all phases of flight. Add in a little wind, and groundspeeds of 10 mph are pretty common. Since we're used to watching regular airplanes fly by, it can be really hard to gauge how close or far away a paramotor is. And therefore whether it's complying with rules.
- I have met people flying paramotors with many different "backgrounds" (shall we say). Some fly paramotors in addition to, or instead of, regular aircraft because they're fun - like me. Some fly them instead of regular airplanes because they're much less expensive, or other practical reasons (no hangar required, easily portable, etc.). But, of course, some fly them because it's their only aviation option - they would not be able to pass, let's call it the various checks and balances required to get a pilot certificate such as a medical, often for various lifestyle choices. There is most definitely a more "free spirit" aspect of this hobby than regular aviation - similar I'd think to many skydivers or surfers and other extreme hobbies. And along with that often comes some hazardous attitudes.
All that said, I'd go ahead and approach the paramotors when you see them. Start a conversation. They may be extremely ignorant of the risk they were imposing on themselves and others. And believe me, the thought of flying a paramotor and getting close to other aircraft is SCARY. Nothing is going to end well in that scenario. So they may be very open to being educated on where the approaches are and such. You just have to make sure to approach it the right way so it comes across as mutual concern, not as "you guys are idiots" - that will immediately shut down any useful communication, just like in any interpersonal interaction. Because they may have no idea they are acting like idiots!