This is a topic that gets a great deal of attention, and for good reason! Because this is Revised, and we like The Golden Rule, we are going to apply a few 'common sense' items that everyone should be able to agree on before we dive in.
1. Blush of Health Merit isn't mandatory.
2. It's possible to Spend Blood Points to artifically create a "Blush of Health" for the evening.
3. Some books (game books and novels) give conflicting views on fingerprints.
4. None mention the SKIN CONDITION for kindred that don't use Blush or it's "per spend" counterpart.
5. Eyes appear normal most of the time (we're ignoring crying for the moment).
6. Voices work normally.
Let's think about eyes for a moment. For those who have allergies, chronic dry eyes, or have undergone eye surgery, you know that eye drops to increase lubrication is a must or else the eyelid STICKS to the eye and damages the tissue (and it's horribly painful). If the Kindred body uses blood as a lubricant for everything, meaning the body is not producing any fluids at all, that means all kindred would be walking around with red tinged eyes constantly! Talk about breach!
Voice. Have you had to talk with a dry throat? Been in a presentation that ran longer than you thought, and you didn't have a bottle of water? What happens? Your voice gets raspy, cracks, even just cuts out. The saliva your mouth produces regularly helps prevent that, along with the mucus membranes in your mouth and throat. Do you think a Kindred is just constantly seeping small portions of blood into their mouth/throat, recycling it all night? Seems a little odd, and like it could be problematic, right?
What happens when your skin gets dry? It flakes, it gets itchy, it looks bad. If waking up restores a Kindred body to the condition it was the night it was embraced, and the skin was healthy that night... how is it being healthy again now, without it looking like a thin sheen of pink is on it? Their body must be producing oils for their skin. Or else, as the nights went on, without blush of health, Kindred skin would turn to dry leather.. cracking and flaking off.. and sure, Blush of Health or burning BP to getting the heart pumping helps with that, but still, if the skin isn't coated with a very fine film of blood, what's keeping it supple?
In short, the Kindred body uses that Point of blood to 'jump start' critical functions that allow Kindred the basic ability to blend in with Kine. Saliva production, tears/eye lubrication, oils in the skin (so yes, all Kindred do leave fingerprints!). Now, if your Kindred cries a little, it should still be normal tears... if they're crying like Niagra Falls because it's like ten of the worst things to ever happen all hit them at once... maybe the tears would come out a touch pink as their body tried to keep up production. We personally don't recommend it, but if you want to play it up for effect, you can.
Kindred and sex
Another often commented topic, and more directly handled in later systems (Which we personally don't like because it takes the "role" out of the "play" and makes it very mechanical instead). Kindred are predators, and they know there are a number of ways to get what they want. In the Revised Core book, and Revised Torrie book, and Novels, there are comments made about how high Humanity Vampires, and the Toreadors (assuming also with at least moderately high humanity, like 6+), are "so close to human, some of them can even have an orgasm".
This is compared to other systems that think somehow being Kindred is going to make you forget the fairly basic muscle memory to having sex. Maybe if your Kindred were a virgin, or a Kindred for hundreds of years without having sex, this would be reasonable (but still laughably funny), but in general, it just doesn't make sense. For the most part, we suggest that Kindred consider sex as foreplay, leading up to their main O-face which just happens to include driving their fangs into their victim and drinking their blood. If you want to have a Kindred that can still enjoy sex even without feeding, that's fine too! If your character is literally going through the motions just waiting for the opportunity to strike and is so bored in the meantime they consider what color to paint the ceiling, that's your call!
If even thinking about the act of sex is just disgusting to them because 'We Kindred are so far above the cattle.', that's okay, and now we know you're probably playing a Sabbat!
The short of it is... like with many other aspects here, we let the player decide what is right and normal for their character, and to make responsible choices in the contest of that character.
Where is all that blood stored?!
Yet another topic of debate and discussion. A common thought is "the stomach". Again some books and novels hint at this, including Kindred of the East. But that concept breaks down with low generation vampires that can store significantly more blood... and they're not walking around with beer (blood?) bellies!
Our explanation dives into the 'mystical' side of Kindred here. The blood is concentrated and permeates their body. It's why a freshly chopped off limb can "reassemble" itself, tendrils of blood extending from both sides when in proximity, and pulling it back together like, well, a monster. Or the T-1000.
This matters mechanically, if your Kindred has the Eat Food merit, or just passes the roll to keep something down without it, when they go to -ahem- expel it at the end of the night, they're not going to throw up a point of blood with it. Just like with skin, eyes, etc, their body will generate some bile or acid and out it will come.
It also means if a Kindred is shotgunned in the gut, or slashed across with a Katana, they're not going to lose the majority of their stores of blood (if they did, can you imagine how many more Kindred would be frenzying all over the place, and how easy the Sabbat could stir up shit?).