Personally I would not go with Elizabeth if you don't want to use nicknames. My niece is Elizabeth and her parents were adamant that they would not be shortening it. But she at age 10 she gets Lizbeth, Liddy-Beth, Liz, Lilly, Lilabet, etc from family and friends. She chose Lilly as a nickname for school as otherwise she was getting Lizzy which she doesn't like. It's a name that is made for shortening!
On the other hand if you are not particularly against nicknames but just not planning on shortening it yourself, then any of the above are gorgeous (have to note a personal preference for Lorelei which is adorable and one that has been vetoed by my hubby so I'm happy to see such a lovely name being used by others :)
If you are not wanting to shorten/nickname my choice would be first Caroline, then Lorelei, and third Elizabeth. I know one adult Elizabeth that actually goes by Elizabeth. She is an sweet and lovely person so that just adds to the name for me. Unfortunately, 99 out of 100 times it does seem to be shortened. I personally love the nn Libby.