Are you American, and did you (like most Americans) buy the phone through a carrier? US carriers often do force updates on phones with their firmware, whereas phones elsewhere in the world, and non-carrier US phones, allow you to choose whether to accept updates or not. If you are then I'm afraid that explains the annoyance of it being forced on you, but doesn't provide you with any remedy.
Oreo is Android 8, though what you get is Android 8 plus Samsung's changes plus (if you bought through a carrier) the carrier's changes. Since I don't have a Samsung running Oreo I can't advise on most of the thing you mention since they are different on my Pixel (also running Oreo). Actually I don't kow what you mean by the "apps to drop down when I'm using the phone". Since Oreo on Samsung is very new I can imagine that your search results mostly refer to the Android 7 settings, which could explain why they aren't helpful. Hopefully someone else who has this phone will be able to advise.
However, the notification badges I do know something about, because we've had a lot of queries about that. In 8.0 Google added a default "notification dots" option to Android, and Samsung have chosen to use that rather than their own implementation. What others are seeing is that you get a dot on the icon when you have a notification (rather than a count), and when the notification is cleared the dot disappears (even if you've not read the message it is notifying you of). So I'm a bit surprised that you talk about 2 apps having numbers showing: are you using the Samsung launcher or a third party one? Most people are saying that they want the numbers back, and the answer to that seems to be to use a third party launcher (such as Nova plus the TeslaUnread plug-in) to get the number badges back (and behaving the way they expect). Maybe if you can tell us which apps are showing these anomalous number badges, and do they have any unread messages (as opposed to notifications), this might give us some clues for that problem at least.
