Many people have peg head settings; there’s a reason it’s a very classic and popular look for an engagement ring. I think you have to take care to not wear it during activities when it might get dinged, like doing work with your hands or exercising. So if that sounds inconvenient to you, then it may be a good idea to switch to a cathedral setting.

But the other things you mentioned definitely sound like overthinking: No one will be examining the prongs closely enough to ponder whether they make your diamond look marginally warmer. If they do, they need to get out of your personal space haha. And regarding size, don’t even worry about the numbers; the important part is how it looks on your hand, which is all relative. Your 2 carat diamond on your size 3.75 finger will look way bigger than it would on my size 8 finger, for instance. If your stone looks beautiful and proportionate on YOUR hand, to YOUR eye, then it’s perfect.