With the body, you have a good reference and have matched the shape, but you need to get some more loops going on around the hips join area, under the ribs, arm joins and so on. At the moment most of the body is like a deformed grid. Just look at other mesh models, all these things have been sorted out and you can just use the same poly flows.

I understand you will probably take it into Mudbox but you should still try to get a good poly flow. Everyone has something to say don't they. I think it's coming along really well, you have a nice base mesh that you can fix up.

Have you seen this free app for generating meshes, it's worth looking at just to see their idea of good flow. You probably want to do it all yourself but, otherwise what's the point right?

https://www.makehuman.org/