Here are a few of my random thoughts as a person a couple of years younger than you who has been traveling in a motorhome part time up to 75 nights per year for the last 8+ years, mostly on trips that are a month long or less.
First thing shop for the amount of living space you need, don't worry about the vehicle size, a small Class A is not a much larger box going down the road than a Class C, it just has a different seating position which you would get used to in just a few days on the road. Consider going out and renting a gas Class A around 30-32 ft long and trying it, sure it may be white knuckle driving for the first hundred miles or so, but by the time you get 500 - 1,000 miles under your belt it will likely be almost second nature.
Second on the topic of your cars, check to see if they are flat towable or dolly towable, there are many cars on the market that must be towed with all 4 wheels off the ground on a trailer, that is what you don't want. I know that the Miata is not officially sanctioned to be flat towed, but many people have towed them for thousands of miles if they have certain manual transmissions.
Third, Starlink can be great, we have residential Starlink here for the last 2 years, and it has been a game changer, the catch is you need a clear view of the sky, which can be an issue in an RV park or Campground with a lot of trees.
As to the keep you awake at night stuff, there are plenty of campgrounds out there that allow long term stay, the question is how many are where you want to travel, and how much do they cost, where I live in western Louisiana the going rate for most long term sites is $350-$450 per month plus electricity, with $500-$700 per month being fairly common in more popular semi tourist areas. If you are flexible you can always find a monthly spot, the exceptions being prime Snowbird territory like south Florida or the southern tip of Texas. Those $2K per month places are the real RV resorts with on site golf courses, and such, either that are they prime locations like the California coast.
The truth is you can RV travel on as high or low of a budget as you, we had a guy on here a few years ago trying to live in an RV on a shoestring budget, he managed for a couple of years before giving up living in a stationary location for around $250 per month on a less popular east Texas lake with a full hookup RV site with a view of the lake about 20 miles from the nearest grocery store. Even moving around can be done on a budget, we took a circa 3,000 mile /30 day loop trip in May of 2023 to the Badlands of SD and back going through parts of 7 states, the most we paid was $54 per night for 3 nights, 5 nights were free boondock camping, 4 of which was on federal land, another 5-6 nights were under $25 per night this was a mix of Passport America discount rates, and public campgrounds of various types ( water and electric site at a country fairground in Kansas for $17 per night, state park for $24, ..) The state park site we managed to snag with only 2 days reservation on Memorial day weekend.
On your last 2 points there are a number of campground review sites out there as well as google reviews, many will tell you if a campground felt unsafe, though they are less good at telling you if a campground is great. There is probably half a dozen such review sites, rvlife, the dyrt, campendium, etc.
As to off grid power, Solar and LiFePo4 Lithium batteries are a BIG help, we currently have 400 watts of solar panels, and 420AH of 12V LiFePo4 batteries, which is enough to provide basic living electricity without running the generator in sunny weather, ie power lights, furnace blower, vent fans, computer, etc. though I am likely upgrading to 800 watts of solar panels this spring.
