My assumption is that we may not use character names from the fiction published but are able to use actual chapter names.

IE, Robert Guilmane (sp?) is not OK to use as a name, but a random named I create and then use the Ultramarines as the chapter is OK. Is that indeed correct? And if not, how do I change my pre-order? Heh.

Basically, as long as you don't use the name of a well known character from one setting or another, you should be fine. It's the same sort of statement that is used for RP servers on many MMOs.