Re: Darkwar questions (spoilers)
Ok, it's been a while since I read these but I'll theorise away anyway.
I don't know what was between realms exactly but Feist doesn't seem to have attached any significance to it thus far. It does seem to be a general rule in fantasy that if a realm exists something will live within it...
I sort of assumed the glyph was a reference to the gardener, seeing he wasn't exactly of the Dasati world and that the glyph also is connected with a lesser. A bit of foreshadowing of what would be revealed later on in the book perhaps.