Bonus tools has a measurement hud, that shows edge length and distances between vertices. http://area.autodesk.com/blogs/stevenr/maya-bonustools---display-tools
What you're describing is typically called a 'vertical slice'. A prototype is usually very low on the visual fidelity stage but the gameplay mechanics are tuned enough for playtesting.
The thing with this plugin is that you can have your 8 millions vertices ZBrush tool and decimate it. You can't open such an obj in Meshlab, he'll crash.
I suggest you straighten out most lines, to be plain horisontal or plain vertical. Having diagonals + textures of this low resolution will will make blurry edges.
adding und moving edges / tweaking vertices is no problem as long as there is no uv split, just turn on preserve uv's - actually its quite a sexy feature.
floaters would probably be best. you could start it out as a floater, turn on snaps to vertices and cut around the floater's edge. then weld. that's one possibility though it's probably not the cleanest method.
I mean that your limbs (mostly noticable on the shoulder) are just cylinders with some moved vertices. There are no edgeloops to indicate any muscle flow. More about anatomical topology on the polycount wiki
New UV map with mirrored vertices. I grouped the UVs by their base color so as not to make painting tedious or have accidental bleed over. I also changed the proportions as well:
First you can scale them on the vertical axis to make them flat, or press "make planar". Then move manually. At least thats how I would to it, but there might be a better way.