I've actually had some of my questions answered browsing through the forums; however, I wanted to address some issues that may come of my conclusions!
First off, I haven't DM'd since the first edition of AD&D, so its been maybe 27 years or so, but I have played 4e.
I am creating my own campaign setting with my own NPCs, their special pets, summons, etc, but I want to incorporate characters from classic D&D campaigns. For instance: I want an NPC to have an acquaintance or even friendship with both Drizzt and Jaraxle and to call for their aid, and I think I've found a way to do this--but are there rules I must follow in contacting characters from other settings such as Forgotten Realms? I was going to use portals and animals of flight to travel between my world and established D&D campaigns and have the messages sent using the methods above. Any suggestions to incorporating this would be highly appreciated!
I am concerned not only with violating any rules, but also if there are legal complications I should be aware of.