Lore question, human corpse and Pale Tree.
Long story short, no. Sylvari experiences and emotions are sent back into the Dream via their connection, which humans simply lack. Without that connection, a human’s memories or “soul” couldn’t be reborn in a Sylvari.
The Sylvari would be free to bury the human in the Grove (I can’t see the Pale Tree objecting to it), but it certainly wouldn’t have the effects you’re theorising.
The only connection between human corpses and the Pale Tree is that the Pale Tree was planted on the graves of Ronan’s family. It’s theorized that it’s the reason why Sylvari look human (I guess Ronan buried him family dog with the rest of the family… http://wiki.guildwars2.com/wiki/Fern_Hound) but we have no evidence as Zaxares said that the Pale Tree had access to their memories.
While’s that’s the in-game theory, Cure, it’s been stated by Kristen Perry when the sylvari redesign was revealed that the sylvari’s appearance is 100% the Pale Tree’s doing – the sylvari’s humanoid shape is basically the Pale Tree’s abstract view of humans. Thus sylvan hounds would be the Pale Tree’s abstract view of canines.
Why Malyck appears humanoid, however, is the question.
Stop treating GW2 as a single story. Each Season and expansion should be their own story.
Only in Avatar.