Thanks andy_vs , I followed your advice and started with Mr Ink. I am by no means sure if what I am doing is right so I thought I'd post an update of my first baby steps in Ziva before I progress on crucial mistakes.
I used and fiddled a bit with the blendshape script originally posted by @Jake (thanks again!) and posted my take on it in that topic, I am thinking of making it ignore groups/empty transforms as well later on (I am sure this is a piece of cake to someone with experience). I was also thinking of creating some buttons to automatically set up muscles and the names of nodes once I understand the workflow a bit better.
For the simulation I changed the scale a little bit so Mr Ink would be closer to 2 than 1.5 meters, I did not want to be tempted to copy values from the tutorials or demo files. I put together a setup for the triceps in the node editor and have no idea if it is anything like it is supposed to look like, it's in the screenshot below.
The values are as followed "ArcLength (starting = 38.108) / 38.108 = 1" "0.8 - 1 = -0.2" "-0.2 * -1.4 = 0.38". With these values the starting excitation is 0.35, the most stretched excitation is about 0.42 and at around a 40 degree elbow bend and over it turns to 0. The lineOfAction used is that of the bicep and brachialis (should these even be on the same loa?).
I was also wondering if for a muscle like the tricep having two heads would need two individual fiber nodes?
I hope that wasn't too much of a wall of text, again I really appreciate all the help on here!