There is a silicone cleansing brush attachment and could do very mild exfoliation but I see it more as a basic mechanical cleanser. I personally find chemical exfoliation (enzyme masks, AHA toners, BHA toners) more effective than physical brushes.

Does the seller keep 50% of the purchase price if you decide to return the item? This is an expensive item, would be risky to purchase if so.

If you purchase from Theragun, no they will fully refund you if you decide to return within the return window. I cannot speak for other sellers. I also did NOT return mine, but did click through the process of returning it to see and it said I would get the full price + tax back. I added a video showing this. (I almost did not purchase because I read those reviews as well, but Amazon has always gone above and beyond whenever I had issues so I decided to go ahead and purchase!)

before and after image of the eyes: what was used? just the light?

None of the lights should be used around your eyes. Per my ophthalmologist this can cause vision changes.

Can I use this on my eyelids?

I don't think it specifically addresses this anywhere (I don't have the manual in front of my so I could be wrong), but I do use the cone shaped percussion tip around my entire eye area on the lowest setting. I get a lot of puffiness in my eyes and hold a lot of tension there so I love it for this. So again, I can't say for sure if it is meant to be used on eyelids, but I have used it there. Hope this helps!