Do whatever you want, you don't have to follow the social norm. Try not to worry about what other people think. An engagement is between you and your partner, so it only matter what you both want :)Lots of love xx
You seriously go with whatever you want. Tradition is nice, but marriage, or in this case, engagement, is a very special, personal thing, and you should celebrate it however you see fit. If that means getting a necklace that you'll love over a ring that you don't really like, then go for it. When my mum and step-dad got married, they had the same kind of thoughts. My mum went with the ring because she would wear rings anyway and it suited her, my step-dad on the other hand, got an engagement watch, a very expensive one, that he only wears on special occasions. It wasn't realistic for him to have a ring because of his job in manual labour and the stains on his hands from being in that industry for almost 20 years. He does have a wedding ring, but he can't wear it most of the time. Also, my mum had a dark blue wedding dress. You celebrate your engagement however you want to, don't let narrow-minded people deter you. It's not their engagement, it's yours.
You are a unique person, and every relationship is different. And you're right, it IS none of their business. I have some experience with this, so I understand how hard it is not to care about other people's opinion. It's a long, slow process, but as long as you and your fiancee love each other and are happy, that is all that matters. Tradition is just social convention. You do what ever you want.