To answer your last question first - NEVER! Well, you probably won't wake up in the middle of the night worrying about these things after awhile, but the problems, concerns, etc. never go away. It's just a part of the lifestyle and you WILL make mistakes - just ask any of us who have made some whoppers!
As for Passport America - absolutely love it. Are there inconveniences? Yup! Do some of the parks have impossible restrictions on lengths of stay or times of the year? Yup! Are there often parks that say they no longer participate? You betcha! I've found some really bad parks, but I've also found some really good ones. More often than not, they are along major arteries and fairly easy to find. When Sharon and I visited Texas a couple of years ago, we used PA almost exclusively! We found PA parks near every place we wanted to visit. Most we could call ahead and reserve or at least ask if they thought we'd be able to get in. So a ton of money was saved times two! I'm also a Lifetime Member of Good Sam, but certainly didn't join for the 10% discount on camp fees! There are other copycat memberships (Camp America, etc.) but usually they are the same exact parks offered by PA. A lot depends on the part of the country you are visiting whether you are happy with PA or not.
This is not to be confused with memberships in Thousand Trails or Coast to Coast, etc. That's another whole ballgame. I'm not a particular fan of KOA because they tend to nickle and dime you for amenities and so many of their franchises have gone down hill in the last few years. Now I'll probably be beat with a wet noodle by those who love KOA. Again, depends on the area visiting.
Hope your experience is positive.
Pooker