Knacks and Domains

I think what you need is to find a way to DEFINE what your vampires can do in a systematic methodology, then you can better work our what they can and cannot do. May I suggest the following system

Knacks: What the vampire can do
Domain: What the vampire can effect

Domans would include Animals, People, Objects, Self, Earth, Air, Fire, Water, spirit, time, Thought, Dead, Wealth, Area. The level should be say, 1-10 just to properly indicate how much one can effect the given domain. one being a passing control over it, to 10 being God-like. 3 being your typical vampire.

Knacks would be what the vampire can do:
Aquiferous - Control over fluid, and by its implications, blood. Healing with blood, understanding the tides and thus perfect time sense, how to make someone explode with a geyser of blood.
Cacophony - more of the classic Banshee, your voice becomes a weapon, Compell people to dance, summon people with your voice
Discordia - Unbridaled access to chaos. Lets you do all those classic weird undead things. Swarms of insects and crap. Make things rot, kill plants with a touch. Drain life with your gaze when you get strong enough. Also would allow a vampire to harness the whirlwind and move faster, giving them greater speed.
Dweomer - The ability to put your power, or other powers into an object. Focus the blood and empower an object.
Fearmongery - Embracing the power of nightmares and attacking people in their dreams, also communicating though dreams. At high levels, you can manifest dream objects that are of semi-reality.
Geotaxis - Power over the earth. A vampire needs the earth of his birth, but perhaps only those who use Geotaxis. It would allow them to manipulate earth, pass through it like a swimmer, make graves open and close so you can just be swallowed up by the ground, rather then needing a coffin. Could make the vampire tougher. The More GEotaxis, the harder his skin and the more abuse one can take. The death of a master would be a massive earthquake (The classic 'My castle colapses' when the vampire dies.) A vampire could make objects weigh less, thus giving them great strength or allowing them to 'fly' because gravity simply doesn't apply to them.
Hearth - Control over your domain. You 'Know' what is going on in your area and have clairivoyance and clairaudience in such an area. Such vampires know where everything is in their homes, and are perfect hosts.
Illuminus - Control over light, like turning invisible or actual light illusions, that have no substance, but can be seen by cameras (as opposed to mental illusions, that could not) It would alos allow for improved senses and the ability to percieve things. Masters would see the truth in all things, no disguise would work against them.
Mesmerism - All sorts of mind control and enhanced charm and any sort of mental illusions. Telepathy, mind reading, Mind raping.
Null - The ability to manimulate the nothingness. Vampires are ultimately life force sinks. A vampire could drain the essance from anything, Absorbing all sorts of energy, like kinetic energy, or sunlight, or whatnot and send it away to the void that is within all of them. Make objects stop existing.
Shade - Vampires are beings of darkness, so they could manipulate Shadows, Steal someone's shadow and have power over them. Turn into a shadow. Attack people's shadows and hurt them. Toss someone into an Oubliette of darkness, making it a shadowy prison
Flux - The ability to change shape of things. grow Claws, Turn into a bat, or wolf, turn into mist

Anyrate, the Knack is what they can do, but the Domains would be what they can affect. Someone with Discordia could speed himself up by controling chaos if he had the Domain of the dead, but couldn't speed up a Human, unless he had the domain of people. Someone with the Domain of mesmerism and animal domain could control rats and wolves, but not people.

If you took the time to explain this, then you could have all sorts of wierd Vampire powers and yet explain why they all couldn't do the same things. Not all vampires are nearly indistructable, only those with Geotaxis and the Dead Domain. The same vampire couldn't mind control, because he didn't take the time to develope that power.

Then you get specialists. Fearmongers are the communication network of the vampires, for example. All vampires get an APB broadcast during the day while they sleep about Human activities.

Enchanters/mesmerism experts control the minds of the human slaves making sure they guard the hives of vampires during the day.

You get the idea. My point is, by having a framework that explains what the vampires can do, even if it's only loosely explained, it would make it easier to understand HOW the vampires can do something and thus suspend disbelief.

Vlad can shatter the door with his hand, he's got the Objects domain and Null. Then when he reads Someone's Mind, we know he's got mesmerism and People. Thus when he 'reads the mind' of an object to see what happened in a room, we know he can do it because he's got mesmerism and Objects. Thus you can combine things in new and interesting ways and keep the audience going 'OOO! I did not see that coming."