You should be able to view the whole game screen while in windowed mode if you want to - maybe try hitting the Maximize button in the upper-right. To get to full-screen mode, when you first launch the game, there's an option for Game Resolution at …
To me it's when the devs give you toys to play with, and you're left to your creativity to come up with something. The less limited your options are, the more 'sandbox'-like it is (so CoH/CoV has a nice 'sandbox' feel in the character creation, but…
As others have said, if you're not comfortable giving your credit card info for a trail, in the case of Ryzom at least you just need to read all the information presented and be aware of the various options. I'm about to enter my 8th month as a Ry…