I need some tips to make my own character based on M4/v4

Some time ago I want to do a pair of characters based on m4 and V4 (I attached a picture for reference)

I've done morphm4 and v4 with Zbrush (not as extreme)  and before starting I would like to ask some advice to those who have experience in character cereacion

My first question is:
What initial position that you you recommend me to export the character to sculpt ZB to start (I show  some positions that I usually use), or a character of this style should be creating separate by parts , in this case , how?

My 0 poses:

http://imgbox.com/pjy7AUZd
http://imgbox.com/Kvr10gS7
http://imgbox.com/7aWExDlW
http://imgbox.com/OIQ9yqeF
http://imgbox.com/noEWK1gy
http://imgbox.com/1T6MKEg4

second question:
As you observed as a character (type or Freaks or mr hyde) that modifies so much  the original m4/v4  mesh (the width of the shoulders, waist, muscles, height, etc ...)
then to I can use the m4 poses, I  should re Rigging?

probably have more questions when working but these are what I have before starting ,any other advice will be welcomed