Wow, did this thread wander a bit
Sometimes I think it makes for a more fun discussion.
Ten year rule - we have never seen that cut off in the Northeast and on two cross country trips in the past three years never encountered it either but do understand that some resort CGs elsewhere are starting to add that to their "Rules". If your 5er is over that age 'limit' and are making reservations in advance, a call to the CG followed up by an emailed photo may cure the problem (unless your 5er looks like a rolling junkyard).
Big dogs with a reputation are a problem and certain breeds may be in the CGs insurance policy, right or wrong. Our 'home' CG does not have breed restrictions but there are some folks that should be banned along with their aggressive dogs. regardless of size.
A 20-30 amp RV of some sort in a 50 amp site - they probably paid the extra bucks for that site for whatever reason. Would I liked to have had that site, maybe, but then 30 amps is
usually all we need unless it's brutally hot and we need both a/c units on. I dislike hauling that heavy cord out unless it's really necessary
Boondocking -in the Northeast - that's usually Walmart, Flying J or some other parking lot. Most NY State CGs are boondock parks but once our RV passed 30-32 feet, is basically left out - unless you want a very poor site. Our last and SOB (33 feet) was setup with solar panels, batteries and an inverter and was used for boondocking.