Hi! I think both pairs look great on you! You have lovely earlobes! I am the opposite, I have small earlobes, so big earrings don't quite work for me in many ways, and I can't wear dangling earrings. Bummer. So no... your earlobes look fine!
I think if you add a longer post, unless you have thick earlobes, it may be too long in the back. Have a your significant other/friend take a photo of the back of your earrings and see how far the post sticks out. I asked my husband to do that, and mine were fine as the post still went past the omega clip. I did not need a longer post which I was totally convinced I did, but the photo proved me wrong. On loosening... I would only do it if after wearing them for a day and if they hurt your ears. I think if you loosen them too much, they will droop. So wear them for a whole day and see if they hurt. Visually, I think they look great on you and only you will stare at the exact positioning of how they lay on your earlobe. Everyone else will see the dangles and be mesmerized.
I like both on you.. the two motif is a bit more casual. The oynx in the 3 motif makes those earrings really pop. You can't go wrong with either! If you can both, I vote yes as they are very different. If you can only get one, and assuming your everyday look is dangling earrings, I would get the 3 motif... those really pop on you!