If I may first preface myself, I didn't pour over the information in this topic extensively; I more skimmed it. So if I reiterate something that's already been beaten to death, just give me a time out.
5. What's the nature of the new ending? Is it an outside vision of canon where Crono's actual trip isn't canonical but what he witnesses is? Does it really take place in the context of CT?
I think most have agreed these events are canon, but the party has its memory wiped. It's really meant as a glimpse for the player to tie things in with CC, kind of like how Kingdom Hearts: Chain of Memories ties into Kingdom Hearts 2. The game provides extra backstory and explainations to certain things that happen in KH2. Like in CTDS, the party has its memory wiped at the end of the game. You know what's going on, but for the characters, it's all new.
6. Postulate ways that Dalton could have achieved the Fall of Guardia.
While Dalton is a bit of a bumbler, he does possess some serious power. He's also shown to be ascertive and influential. As soon as the Ocean Palace collapsed, he got his troops to rally around him as the new king. Earlier, he says he won't hesitate to kill Schala, as he doesn't fear the queen. He equips the Epoch with wings and weaponry. Clearly, he is a competent military leader, and in the five years leading up to the Fall of Gaurdia, he could have improved his powers and convinced Porre to rise up against Gaurdia. Perhaps he also had a hand in what became the widespread use of elements in 1020 AD. With his knowledge of magic, Dalton could have made them part of his military might.
7. What the hell is the Lost Sanctum? A dream emanation from the Dream Devourer, or somehow a cause of the Black Omen? (The Black Omen's creation takes place soon after Schala meets her end and starts merging, of course, depending on how this is viewed through Time Error, since it also depends on Lavos to die, and he hasn't yet in that point of CT's story)
I haven't pondered on this much. I'm assuming it has something to do with tying together the evolution of the Reptites into Dragoninans. What that tie-in is, I don't know.
8. What's the nature of the Reptite artifacts like the Prismastones and Dragon's Tear? What about the antagonist monsters who plan to kill these Reptites?
Good question.
9. What's the canonicity of the Dimensional Vortex dungeons and Crono, Marle, and Lucca's fights with their inner selves? Why would those be in there for those characters and not the other ones?
I like the theory that they are similar to the trio that appear in Chrono Cross. Ironically, Crono's fight is under Leene's(or maybe Nadia's) Bell, and Nadia's Bell does appear in the Dead Sea. Marle's and Lucca's fights take place in the respective room of each character, which I find interesting. It seems to symbolize childhood, and the trio do appear to be children in the Dead Sea.
10. Do you know the Muffin Man?
No.
11. If we believe that the Dream Devourer is a pre-evolutionary form of the Time Devourer, the question remains -- how did Lavos survive to merge with her?
I know the idea of a Lavos spawn actually being the Time Devourer is largely unaccepted, but that's what makes the most sense to me. There was a Lavos Spawn in the Black Omen, after all. That doesn't say much, but it shows there could have been other spawns. One could have merged with Schala into the Dream Devourer, who Crono and the gang failed to stop, and it then matured to the Time Devourer. Maybe it was Lavos' backup plan. His nature is to pass on his DNA to continue his cycle of feeding. He may have saw merging one of his spawn with Schala as insurance that the cycle would never be interupted even if he himself was destroyed.
12. Can we assume that Magus's wake-up to Schala is the moment Belthasar took advantage of when planning for Schala to be awake long enough to create Kid? (This means Crono's presence pre-Lavos is non-canonical)
I don't quite get this question. Even if it is the moment he took advantage of, how does that make Crono's presence non-canonical?
