Etsy itself doesn't have any products... it's a platform for individual artisans to sell their wares. So the milage you get is 100% in the hands of the artisan you are purchasing from. I wager Etsy offers some sort of protection policy, kind of like eBay does. Neither I nor any of the folks I know IRL who have used it have ever had any problems with it. Unlike megacorps, individual artisans have a lot more to loose from a single unsatisfied customer, and they'll tend to treat their customers like actual human beings instead of resources to be manipulated.
Online book reviews of Neopagan literature could be a topic in of itself... one I'd probably go off on a rant with. Reviews in general are usually garbage because most people don't know how to write them properly, but it is particularly bad when it comes to something that has an inherently subjective value, like religious inspiration (which is what Neopagan literature provides). I just say read everything, because everything can have something in there that inspires you.
Oh, and making homemade loose incense is actually super easy. It's if you want a binder and shape it into cones or something that it gets more complicated. Not something I've tried yet. But with loose incense, you just get together a bunch of aromatic plant materials (if you know your botany, you can use local, native plants for this), grind it with a mortar and pestle a bit... done. That's all there is to it. Add essential oils, if you want, but that's optional.