i agree with it except for a few different things. the "vampires are dead" and "they are weakened by crosses" i have a separate issue with the garlic thing but i wont bring it up. but depending on what vampires youre talking about then you can say theyre dead. the ones from the vampire chronicles (interview with a vampire) are dead by definition. but then theres the ones from 20 days of night. theyre more like a jet engine, the more feul they have the stronger they are but it runs their body. theyre alive but when not drinking blood theyre essentially in idle and in a catatonic state until they get the feul to have their vampiric power. now the cross thing. once again depends on the vampire youre talking about, theyre not holy creatures or demonic creatures in most incarnations, that whole myth was made during the early/mid 1900's when the dracula movies and the hammer films started coming out and just followed from there. now onto vampiric intellegance! by all accounts, all types are sentient but its just a question of whether we're seen as a food source, a herd so to speak, or are you talking about the romantic vampire (not twilight, but dracula, etc.) which sees humans as a food source but tends not to kill them but turn them into vampires.

tl;dr theres multiple types of vampires, but no matter what the twilight ones are retarded