Now we're getting somewhere on the warnings.
Buckner's advice is dead on (pun intended again). There is a huge load on the prop blade where it is being driven by the spinner. AND.... keep in mind that load is equally difficult for the spinner's driving structure. So....
When you're looking at spinners, look for adequate bulk and materials in the parts that are actually carrying the prop. You'll notice quite a lot of the glider spinners use smallish hardware and it's often lighter metals. Sometimes it's not metal.
I know that the spinner/prop sets I've used for my gliders all have bothered me since day one. My first impression when seeing the less than robust bolts used by the first setup was, "jeez, this sure wouldn't work on a glow engine." I considered retrofitting to larger bolts and have every time I've flown. Why haven't I? Because it's nice to have a weak link in the system to protect the more expensive electric motors. And that has been proven at the field.