From a biological stand point you’re right, but this in no way diminishes the possibility of trolls having external ears, pointed or otherwise.

Again, made by a fan = not canon

Nope, just the player planets and the Beta’s Battlefield

Right, the whole point of the minimalist character design is to allow fans to give characters whatever physical traits they see fit. There’s is absolutely nothing wrong with headcannoning that trolls have elf ears, it just is not canon, that’s all.

Those interpretations were done by fan artists and hold no canonical power over character appearances.

No, I believe it to be when one is under a great deal of horrorterror influence but that’s debatable, and I’d say no but some say yes.

Yes

Because the Rings are of Void and Life which are Jane and Roxy’s aspects. Heart and Hope are Didk and Jake’s so, scepters.

You can read the full theory here.  But in short, when a player is overly resistant to their role or if they are corrupted by an outside source then their role will inverse meaning that their aspect and class unofficially shift to their opposites. Light to Void, Space to Time, Witch to Seer*. 

*This can change depending on how you classify the classes into Active/Passive partnerships

Grimdark can cause inversion like it did with Rose (making her act more like a Witch of Void) but since we’ve only seen one instance of grimdark we don’t know if it inverses the afflicted’s classpect every time.