Proper nightmare? Elderly folk can be a bit set in their old-fashioned ways and curtain twitch a bit much too much sometimes but I bet you don't have many actual problems with your neighbours other than them snooping on you from their window? I'd rather have elderly neighbours than younger ones that's for sure.
When I say a proper nightmare:
1. Reported me during lockdown for having someone round - I did, an emergency glazier to replace a shattered bathroom window.
2. Reported me for "running a mechanic business" from my house - Friends come to me to fix/fit bits, no charge just doing what friends do (well they usually bring me breakfast/lunch)
3. Reported me for running an AirBnB - I had friends from overseas staying for a week
4. Shouted at my kids & tole them they should play indoors and not in our back garden during the summer weather which upset my then 5yr old daughter and she didn't want to go out.
5. Despite most houses around here being extended, went on a leafletting campaign to object to my opposite neighbours single storey extension.
6. Called the fire brigade to the same neighbour's house because they dared to have a party and fireworks display on Nov 5th
7. Openly called my asian neighbour a peadophile because he gave my kids some sweets (being Muslim his family can't eat gelatine so gave the sweets they were gifted to my kids)
8. Placed tacks under my wife's tyres (seen by a neighbour who cleared them up) because she dared to park 2 inches over the "property line" outside their house (on the public road)
Is 8 enough examples?