All this has been answered about 200 times in 100 threads before.
1. No.
http://forums.wolflair.com/showthrea...=Cloud+Dropbox
2. Yes, same thread for the answer. Only exception: Creating the Realm, which doesn't even require a subscription only an active Internet connection at the very moment you want to create it! After it has been created you can take your PC to the deepest cave with no internet connection you can find and use it there.
You will only need a internet connection after that if you want to create another realm.