Regarding the idea of the ejector striking the primer and causing an out of battery discharge, I'd be curious on the stats on how often this occurs. Personally I see one's hand being at risk in such an event only if they ride the slide forward, or grip the slide too far forward in the first place. If they power stroke the slide, I'd imagine their hand would be clear should such an event happen.
As for slide stops getting worn out, I'm curious as to why people are so worried about a slide stop getting worn out but they're happy to accept the fact they will likely need to replace springs/barrel/ejector/etc during the course of ownership of said pistol. The slide stop is a part of a machine. Parts in machines get worn. If you're worried about wearing out your slide stop, buy an extra one and keep it handy. It's called maintenance. If you end up not needing the spare part, I'm sure that someone on here would be happy to buy it off you. Based on casual observation, the ones who worry about wearing out their slide stop are also the ones that may put 100-200 rounds through their pistol in a year, vs the ones who run through that many rounds in a week.
Regarding which method is best, they're both fine. Travis Haley has said that the power stroke method is consistent across semi-auto pistols. If you're not confident at disengaging the slide stop, then save yourself the hassle and rack it. He's also said that if you can repeatedly and reliably disengage the slide stop, then do that as it's one more skill in your toolkit to get you back into the fight/competition/whatever as fast as possible. I agree that releasing the slide stop is faster, provided that you practice it.