I agree that when new from the factory, the boats come ready for cruising. And Ranger Tugs gets credit for that, big time. Still, ready for cruising means minimally so, not optimally so.
Lifevests: what you will get are the orange fabric, foamed filled kinds. They meet coast guards regs. But the only PFD that will save your life is the one you have on. I don’t know any serious boaters who count them as primary use PFDs. Buy something you will wear, if not whenever on the water, at least when docking and under any less than ideal conditions. For most, that means an inflatable vest, which vary dramatically in price and features. Even the cheapest (and they can be had very cheaply during the seasonal sales) are world’s better than what will come with the boat.
Fenders: you will get four. If you will always know what side you need to dock on, four is plenty. But if there are times you won’t, you will want fenders out on both sides. Two per side may do in easy docking situations, but three per side is better. We carry six fenders at all times, and you won’t catch me with fewer.
Lines: same thought as with fenders. You’ll likely get three. That’s enough when you know the side you’ll be docking on. But in less certain instances, you may want to be set up to go to either side without moving anything around. In that case, you’ll want at least a total of four (bow and stern on both sides), and maybe six (bow, stern, midship on both sides). On sale, lines are not a big expense. I’ve got more than I can justify, but I never regret it.
Back up horn: not mandatory to have, so you don’t need one to be cruise ready. But get one just the same. Not a big expense.
Safety kit, flares, fire extinguishers: what the factory provides will serve you well, and the fact that the factory provides them is a hefty savings. At some point, consider getting an “electronic” flare. They don’t expire, and are getting less expensive quickly, and are not much more expensive (and maybe not more at all) than a new set of flares, which expire at some point. Once you have one, you won’t have to worry about fresh flares, only fresh batteries. Plus, they are easier to use.
Bottom line: what the factory provides is a big plus, but consider better PFDs from the get-go; a few additional fenders and lines are likely things you may want right away too.
Congrats on the new boat!
Gini