Nooblet, thats quite a bit of flow. Probabaly more tham you need. I think if you put stems in there not only will they lean, but you might even have trouble keeping them in the substrate at all. Is the output on your filter adjustable?
As far as the trim is concerned, some believe the safety is related to the size of the aquarium. Keep in mind however, that the top of the glass is not "finished" amd may have a rough/sharp edge to it.