In WSS there is a possibility to add new Site Groups aside from the
default like readers, contributers, administrators.... is it possible
to add custom rights like this user can access certain folders or
this is a first level approver for a certain document in a certain
document folder?

Is it also possible to specify the approvers in content approval of
documents? In SPS these can be done in in the dashboard, how about in
WSS??

i am more used to managing SPS than WSS, i have been toying around
with WSS for only two days and i am newly hired. if my queries above
are already a built in feature, can you tell me how.