The maintenance issues are really not too much of a big deal, especially on a unit just a a few days old. I'd say many folks on this board are more interested in making mods to make things smoother and not as much in repairs. But make no mistake about it, it will take more attention than a hotel room, that is certain. If you have internet access, you can post questions here about problems you have, and they will be answered. It will be the best $12 you will ever spend. And if you do encounter problems, they likely won't all appear at once. You can just take them as they come, get advice here, and learn along the way. That's what we all do. And for the occasional problem that it over your head, pay a shop to fix it.
As far as security goes, I think many people get a false sense of security in their homes, apartments, and hotel rooms. It is very easy to kick in a door, and way easier to simply break a window. On your way home from work, take a look at home many places you could break into with a rock. I get a sense from occasionally reading newspaper police logs that many theives gain entrance thefts to vehicles and residences through unlocked doors and open windows, and the same would certainly hold true for campers. Bottom line: your camper only has to be more secure than your neighbor's. Camp next to a pop-up.
Close your windows and lock your doors when you leave. That's the same thing you do at your house.
Dave