1.Trevor mode doesn't count. It's unlockable after beating the game and is not part of the story/canon.
Whether it's a part of the story or canon or not is irrelevant, you factually said 'no playing as trevor' and I pointed out Trevor mode, where you do, in fact, play as Trevor. I factually proved you wrong and that was the entire point. It doesn't matter what you
meant, because that isn't what you said.
2.You can't just assume what happened to the other characters. Why even make it a direct sequel if you're going to add new characters yet not include the previous characters.
My "assumptions" are based on what occured in their lives at later dates as dictated by other canon media. Alucard felt guilty for his patricide and simultaneously wished to cleanse the world of his cursed bloodline, thus submerged himself in what was intended to be an eternal sleep.
I don't see why you find it so hard to believe that more things happened then we witnessed. CVIII, in-game, was incredibly shallow as far as story is concerned. Simultaneously, CoD and the manga created story that centered around that timeframe yet did not interfere in the already existing canon.
3.Why is there no need to see St. Germain again? Dracula was resurrected many times after CoD. Where was he then?
That was his first resurrection and Death was directly involved in manipulating the course of events that would lead to it. It was Death's involvement that lead to Germain attempting to interfere - I shouldn't have to repeat that. Once it was proven that even
if Death directly interfered in this course of events (which, if I recall correctly, he never did again) that it would in the end be ultimately futile and Dracula's defeat was inevitable, Germain saw no reason to interfere anymore. If we do see him again, it'll likely be in 1999.
4.You can throw around all of your pseudo facts all you want. If memory serves, no where in the game did it say that Dracula was weaker than his usual self.
If Dracula was going to resurrect the same regardless, why would Death bother to even try and use Hector's more powerful body in the resurrection process? Why didn't he just try and use Isaac's in the first place? Because Dracula would be resurrected using that body as a base and a stronger body would have allowed for a stronger resurrect. That was the entire point of a majority of the game's struggles. Someone didn't pay attention when they were playing~
Either way, I still don't feel that anybody should be able to defeat Dracula with any weapon other than the Vampire Killer, including Dominus.
Get over yourself. It doesn't matter what you think; it's canon and that's that, there's no point contesting it - especially seeing as it's been a part of the canon since 1994.