A list of these things would be wise to make, for those we know little to nothing about. But that list will be large, depending on how specific we go.
Discussing them, however, is pointless if we know so little about it. As we can say anything, and as long as it doesn't go against what we know, it has just as much say as saying that the Ancient Dragons will become our allies in GW2. <--won't happen, I'm highly sure, but it's an example of how "anything goes" with these topics.
If anything, this should be a list of things stay away from in discussion due to so little info on them. Of course, not meaning we should not talk about them at all.
Such things I can think about:
1) Giganticus Lupicus (the "giant titan people" you mentioned)
2) Ancient Dragons (despite what the Movement of the World states, we still know very little on them)
3) The Mage Lords (this includes Odran)
4) Origin of Dwayna, Melandru, Lyssa, Dhuum.