the police can put on a convincing job that they're fair, will deal with you straight, and so on
it don't work that way, they're only interested in building a good case, which means your ass in a sling if they work it that way
they threaten to get what they want
however, if the OP's case as it is described, it could work out for you
what you do by cooperating is make the police your jury, if you're way down on the enforcement ladder, you can win, kind of
no upfront jail, but if you're down on the lower part of the enforcement list, they're probably not going to prosecute for spite unless you provoke them
bottom line, cooperation doesn't get you much, unless you want to get in on the informer business