I live in the same situation and have spoken to the the Police and they claim that they enforce only state laws, unless directed by federal law enforcement to investigate or make an arrest under federal statutes. Basically what he said is, "unless the feds tell us to arrest you for the 1000 foot rule, we're not going to because it's not in state law."
I have also walked along the sidewalk on the opposite side of the street from a public elementary, and have been seen by police while doing do and not been stopped. I walk outside within my apartment complex with my firearm in plain view and have been noticed on more than one occasion by police that were on the premises for other business and never been bothered either.
I would discourage you from loitering near the school for any reason, because there is something in State law about Loitering near a school with a firearm, I just cant remember the statute. As for cleaning your firearm in a place that is accessible to the public. I don't see anything illegal in doing so, but it is not the same scenario as someone seeing a firearm securely in a holster on your hip, you have it out of the holster and in your hand in various stages of disassembly. I understand your reasoning for cleaning your firearms outside, but I would find a way to do it outdoors in a place not accessible to the public.