1. I have two of these in my plane and did experience RF interference with one of them. The solution is to add an RF choke to the power wires for the light. Here is the part number for the RF choke: [Würth Elektronik] 74270062 Ferrite core https://octopart.com/search?q=74270062
I have two of these LED lights in my airplane and have not noticed any radio interference at all.
2. Put mine in a lawnmower. Can't speak to RFI in your instrumented environment but they do not produce any thing I can hear in my AM/FM headphones. But given the likelihood of a switching p/s for the LED'S I'd stick with a filament bulb. Unless you can find one aircraft approved like Whelen but price is 10X than HANDXEN.
3. It has not been a problem for me,but I understand a few have not noticed any radio interference at all. experienced radio noise