no, i didnt seal the edges. i didnt really have any need for it. the prop pretty much came out of the mould like that. then i just broke of the thin film excess of epoxy that was kind of like webbing between the blades, and did some light sanding with "wet and dry".
the blades are not really a constant thickness so its hard to say. theyre kinda wedge shaped, with a lot of variable surface geometry. the thickest point near the center is around 4.5 mm, and near the edges the thinest points are around 2.5mm. but thats ignoring the fillets etc on center shaft and blade ends