This is an example of how you could adjust commissions based upon category.
https://gist.github.com/fervous/01c7d017fe6eaaeedbdf8c352701fdfa
Here is a link to our documentation site, and some ways in which you can use the filters to adjust commissions:
http://docs.wcvendors.com/knowledge-base/commissions-as-a-fixed-dollar-amount-or-fixed-plus-a-percentage/
You’d be changing based upon product type, rather than category- but this gives you a starting point.
As for permissions… I will need to check on that. I am not sure exactly how the code would be written.. conditional, I am sure.. to prevent a user from publishing only the one product type vs. all