It may be a bit drastic, but if this is the only library on this Koha system you could try turning each section into a branch and turning on independent branches.
Separate branches would allow for different rules without drastically increasing the number of item types, and staff would be at a certain branch. Turning on independent branches would effectively restrict them to their section. You could even hold the independent branches setting for a bit to see if it works to have each section as a separate branch.