As for unsharp, you can click Tools > Video Effects, and apply a Blur effect
for your video. As for sharpen, I'm not sure this is an option in MM2.
What I'd do is pass the file through a 3rd party application that has a
sharpening filter, then import that output into MM. Of course, if that
application has a sharpening effect, I'm guessing it's better and faster and
more reliable than MM2, and you wouldn't be here talking to us. So, no idea
:-(