Hey Frank,
In regards to the upswept handle it is indeed to keep your hands out of the way. In practise slicks are more akin to planes than chisels. They are meant for paring tenon cheeks and taking off high spots on timbers so the angle of the handle allows the blade to be flat on the work while still keeping a grip on the handle. A little semantics: the tool made in the video is definitely a slick and not a chisel which is meant to be struck with a hammer or mallet and will usually have a metal ring at the end of the handle to limit the mushrooming where it is struck.
Fun video, definitely jealous of the idyllic "shop in the woods".
