Just a few comments as a beekeeper and retired cop.
1. Verbalization of words to the affect someone is going to throw gas on your beehives is assualt. Assault is threatening action that would inflict harm. Property can be assaulted but is usually applied under reckless disregard. Verbalizations that can harm people or animals is acutal assualt. I would register a complaint with the local cops IMMEDIATELY to document the threat. It may come in handy later.
2. Grandfatherizations are good for as long as a current owner has the property in non-agricultural areas. In previously agriculturally zoned areas it is good as long as livestock is maintained on the property--even though the property may change hands.
3. Most areas do not have ordinanaces against beekeeping and those that do must be specific as to under what conditions they can be maintained. If you meet the conditions you can keep you bees.
4. Bees, according to NAFTA, are plants not animals. So ordinances concerning them must stipulate the specific genius being restricted--this means if the genius cited is Apis M. s., you can legally keep Apis M. c. or anyother genus as long as it isn't Apis M. s.
Since bees are plants, animal ordinances that does not specify genius is not applicable.
5. Having moved you hives can be seen as voluntary abandonment of protections under constitutional, federal, state, county, township, or municipal laws and ordinances.
I would advise replacing at least one hive on your property ASAP.
The above is not legal advice but my own interreptation of regulations--disclaimer.