Yep. You need PS Plus. I recommend you just stick to single player unless you have a lot of other online multiplayer games that would make the purchase worthwhile to you.
The plane may move around, but the pilot won't lose control. You may not anticipate turbulence in your flight, but just in case you do, you will be safe if...
Consider how expensive the area around the condo is. If it's in an costly area, such as by the beach or a major city, consider giving your friend a couple...
Of course you can't update it, because you aren't online. What you can do is connect to the internet, update Steam, and then display your status as "Offline", even while...