Hi @maxcady ,
Some things that I noticed immediately:
These Faces for instance:

Let’s isolate them to get a better view:

Pay special attention to the selected N-gon and it’s ‘center’ (the white dot); the Catmull-Clark algorithm (Subsurf Modifier) depends heavily on that center point.
If we now enable the Subsurf (one level only here), we get this mess:
In general, when using Subsurf, corners, especially concave corners need holding Edges. This crazy geometry is also visible in Object Mode:

Furthermore, I am not happy with this kind of non-manifold geometry (even apart from the extrusion having no thickness):

I might find more when I look longer, but these rpoblems need ‘immediate’ fixing 😊
Really like the fingers (and thumb) though 👍🏻