Hi concernedone, and welcome to cruise-chat.com.
Nearly all cruise lines have so-called hidden charges -- soft drinks, photos by the onboard photographers, and Internet usage are some examples. Yet, you can easily avoid these. The one you can't avoid, however, is tipping, which on a 2-night cruise won't be much, anyway.
Regarding the upgrade, on which deck is your new cabin? Regal Empress has a wide variety of ocean view cabin styles.