Mother Nature Meets Father Time

Vampire Rules and Such- What if?

After finishing a marathon of assorted vampire classics, my colleague and I were discussing one highly overlooked piece of necessary information: the health of the victim. In Anne Rice's, INTERVIEW WITH A VAMPIRE, LeStatt mentions that blood must come from a live victim, or it would make vampires ill. Other than that minute detail,nothing more is said. Here were some situations we discussed:

Vampires are supposed to be highly allergic to garlic.
Some people obsess over garlic and never experience periods of complete 24 hours without garlic in their systems. Can vampires detect this before attacking? If not, will the allergic reaction to garlic continue to exist if the creature has ingested large amounts of garlic on a regular basis? If not, why not? If so, why do we never see this reaction illustrated?

Vampires are highly allergic to pure silver.
In BLADE III, silver dust infects the ventilation system as a diversionary tactic for a rescue attempt of a member of the "Night Stalkers" team. What would be the result of ingesting the blood of a worker from a silver refining plant, or better yet, one who has retired after spending over 20 years inhaling silver dust?

A wooden stake through the heart kills a vampire:
why must it pass through the heart? What is the stake splits upon entry, and only a splinter actually piecres the heart? If only a splinter could damage a vampire, what about the miniscule fibers which compose the splinter? How would the blood of someone who concentrates on a high fiber diet adversely affect the health of the vampire?

Finally, UV rays kill vampires, except for rare instances of "day walkers".
What if somebody has significantly exposed himself or herself to UV rays, and teh skin is still reacting to the rays. For instance, a potential victim has been at the beach all day tanning, or has just left the tanning salon, and will continue to "cook" for the next 24 hours. Will the blood of this victim cause harm to the vampire? Or does the vampire specifically avoid creatures who tan regularly?

Fell free to add your input or "set me straight" on vampire theology* lol!