However…Some notes:
You’re using plannar mapping, yes. But seeing the texture…you not using a split plannar mapping: It is giving the same texture to the back and front side. I didn’t read all slowly, but if you made the mapping outside zbrush, you should have splitted back and front plannars. Is an uv problem, not a painting or zbrush issue.
The random distortion happens whenever you ‘pick’ your model using texture master. Is due to the way it calculate how the pixels lay down, or something, I think. Workarounds: repaint, do not use too much ‘picks’, think of painting high count models more than low… And some others. At the end (in non low count game models) everything can be made quite hiperrealistic. This thing surely is adreessed in 1.5 (I wish ;D)
The random distortion is not distortion is a slight blur…But if you talkn about the distort in the interior side of the legs…it is for the plannar mapping thing…
You see you have green strokes in the back side of the head. Again, the mapping applied is not correct,(same texture for back and front) you should make a different one. The only thing for free I can think of is www.uvmapper.com , the beta version. With uvmapper, the best to do is create groups inside your modeller, and so in UvMapper it recognizes the groups, and can apply different mappings for head, torso, etc…
There’s a comercial but cheap great app called www.unwrap3d.com for uv mapping generation.
Whatever the tool you choose for mapping, this could be a quick uv set up for a high count model like yours:
For example: cilinder for arms, plannar with split (bottom&top) for hands (if the arms are like in that image -ready for anim ;D-), box for torso(you may sew those uvs later), cilinder for legs (that’s better be done in somewher you can orient gizomo uv cilinders, like in Max or Unwrap3d ), box for foot, cilinder with caps (with some uv rework later) for head.
Till you get to learn (work) that stuff, you wont have all the control you may prefer over the texturing, or that’s my opinion.
or, hehe. You could just import a Poser male and modify in in Zbrush 
Even better. Just wait till 1.5 is released, as those magic new zspheres will have it’s own mapping, generated as you construct, automatically. :-o I f I understood well.
It may be so easy I may feel then I will not be doing 3d…
But software must be geared to that kind of thing, so that artist can access easily to 3d, as it use to be a barrier, and lot of talent is not used for fearing th etechy thing.
Anyway, I recomend to not forget you can always paint over the texture in 2d mode, directly. For some detailing could work well as an aditional technique.
