I agree that the Chestburster could look more scary, guess I'll have to wait for them to do the '79 chestburster to see if there's an improvement and yeah, the fingers on the Facehugger are a bit silly, that pose was really in one scene only in Aliens.
I know it's very hard to do at that scale, but I wish the fingers had a bendy wire or a hinge that could move all the fingers together so that we can have a crawling and a facehigging facehugger in one. At least we have the bendy tail.
I do think we'll eventually get facehuggers pre-posed in a facehugging position that can be easily clipped on other people's faces.