There was an idea from back in mid-2011, about a police departmental pay scheme.
A pay scheme that would govern how much money an officer received within x amount of time, dependent on successes/failures.
I'm not 100% sure on the status of that idea (it was accepted and refined collectively I think), but I think would work the best overall.
---
As for police being able to purchase weapons while on duty - sort of a tricky one, in a way. I'm trying to put together a new guide with almost everything that a member of the AR-VCPD would need, and it includes some of these less conspicuous things.
Hopefully that will clear up the grey areas and be of good use.