In Reply To #2
That manual (it was Symphony's, did Rondo's do it as well?) is inconsistent with LOI as well, as there's no way Mathias was 100 years old at the time of LOI.
Besides, someone probably just messed up with that manual. This site's suggestion that LOI was made purely to justify the manual is probably a bit exaggerrated, but the truth is that there were six years between those games and I doubt the SOTN manual was meant to be some sort of foreshadowing of an upcoming origin story, especially since (to the best of my knowledge) Legends was released in the same year as SOTN to serve as the origin story (although I don't think IGA had any involvement with Legends, correct me if I'm wrong).
Rondo of Blood originally stated that Dracula was around 800 years old in Dracula's profile(on the character section). In SotN, they say Dracula is an "Estimated 800", meaning "give or take" some years. IGA wanted to address why Dracula was THAT old(even though, he, himself, wasn't the one to come up with that idea). LoI Perfect Guide states that Mathias was 32 during LoI, meaning he was born in 1062. That means he was 730 during RoB and 735 during SotN. Maybe leaning more to be an "estimated 700", but I can let it slide. Especially since IGA wanted them(Mathias and Leon) to have some tie to the Crusades(even the First Crusade was to begin a year after LoI).
And yeah, IGA retconned Legends. In IGA's canon, Trevor was the first Belmont(person) to defeat Dracula. Since then, Dracula was, basically, "alive"(well, had yet to meet his end at the hands of a foe). IGA stated that, between the time of LoI and CV3, Mathias changed his name to "Dracula" and hid out in many countries. The Belmonts wouldn't meet Dracula until CV3, and IGA stated that, during the time between LoI and CV3, the Belmonts were fighting "other" threats. He was secretive regarding who these "other" threats were, but it's believed that they are other vampires, perhaps like Carmilla and Olrox. I think, recently, IGA shown some interest in that period(after LoI, but before CV3) when he was discussing possible ideas for the upcoming CV games(the DS one and the next gen one).