Themeforest Item Team Share

Hi all i am Owner I hired a two persons team of a designer (PSD Template and HTML Template designer) and developer (Wordpress Theme Developer). They both are on a fixed salary but i want to give shares on themeforest earnings. So what will be the share of designer and developer with me.

Means the share will divide in three parts
My service (Office rent etc)
Designer and
Developer

Who will be responsible for after sales support, maintenance and updates in future?
You or the same developer ?

and what is your role if you want to split the percentage of sale?
Also are you giving them salary till they complete the theme and once that theme is approved you want to give them a share from each sale?

Your questions are not very clear, please make it available in detail so community may pitch in to answer your question…

We are responsible after sales support and all updates.
My role is manager actually i am creative manager or you can assume me project leader plus owner. I create the design ideas.
They both are my employee and i will always give them salary even after theme approve from PSD to WordPress.
Means if there is no Themeforest sales i have to give them a fixed amount because they work on some other company projects also. But i want to give some share on each earning.

Please tell me if you have any other concern.