Well, most choices matter, some more some less. Almost every time you choose a dialog option different variables end up changing and based on a couple of these changes scenes play out differently. You won't get any warnings before making choices because 1 choice doesn't decide the outcome of the scenes, but the 10-20 or more you made previously will.
The earrings, or anything from the inventory for example, usually will add an extra dialog option or choice in future scenes, there you will be able to decide what to do with it. If you have the earrings or some other item, you will have 4-5 opportunities to use them with different characters, but you can only use them once and based on that you might see different scenes. You won't be able to keep the earrings forever, when you miss all the previous opportunities to use them, you will get a scene where you have to decide what to do with it once and for all. This last option will come down to two options, sell it, or throwing it away... Also those earrings are stolen and you are in possession of stolen property so there's that too. lol
