You could have a lot of fun with this idea if you mess with the lore a little bit.

Feeding dependancy could be something like they feed off the life essence released when they turn someone.  But maybe it takes awhile of sustained eating of their food to change.  They could be in the restruant/food industry, making addictive food and using glamours to make the food look irresistable.  The glamour could also be how they pass as human when dealing with the general public.

An advantage they could have is maybe due to the slow transformation process it means they don't have to feed very often.  Since they basically have one huge meal when they do turn someone.  They also wouldn't need to do much more than keep drawing people to eat their food instead of the competitors, every human has to eat afterall.
I may adopt that for my campaign.... xD

That's a pretty solid idea actually...oh, and for those wondering why I went with these guys over Wendigos, Bukwus are more regionally close to the Vancouver region.

I run game based in Vancouver, and there are a variety of Vampire groups trying to gain ground over the other groups there, and, for fun, I figured I'd add a new court. Then one of my players found a mythical beast that seemed to fit the ticket as a basis. It's called a Bukwus, and I'm trying to figure out how to stat it properly.

Here's some info I found.

Sometimes mistakenly identified with Sasquatch (Bigfoot), Bukwus is actually a kind of ghost of a drowned human in the folklore of the Kwakiutl and other Northwest Coast tribes. It resembles a stylized skeleton with long tangled hair and bloated facial features, and it tries to tempt humans into eating food that it offers. Any unwary traveler who partakes of its ghost food will be transformed into another undead Bukwus.

So far, this is what I have for them...

Bukwus (Blue Court Vampire)
Aquatic (-1)
Living Dead (-1)
Inhuman Strength -2
Inhuman Toughness -2
Inhuman Recovery -2
Catch ?
Claws – 1
Total: - 9

Master Blue Court
Aquatic (-1)
Living Dead (-1)
Inhuman Strength -2
Inhuman Toughness -2
Supernatural Recovery -4
Catch ?
Claws - 1
Total: -11

But I think I'm missing that last bit of flair. Any ideas?

I have a player who is interested in being a focused practitioner, but he asked me, given what he read in the text, what would give that edge in their field?

I just notice that in the books, Mortimer can do things that other Wizards just can't do with Ghosts. This particular player is playing a (Plant) - Mancer, and I was trying to think of something to represent that innate sort of natural control over their element that a full blown Wizard may not be able to replicate easily.

I could be reading too far into this, but that's just what I got out of the books.

Illithids?

And "mosquito" was more a reference to their impact on the level of international/interplanar affairs; individually, any vampire is still going to be deadly.  And when we already have a class of emotion-eating vampires, other choice bits of what it means to be human--our memories--become a viable storytelling option.  And as you said they keep their numbers artificially low, that's what made me think of the three minor courts. 

Oh, yes, the court I was designing would definitely not have enough manpower to really be political players. Essentially, I just need them to help someone create a large group of mindless people, ready for the taking. As for weaknesses, I was just piecing together a variety of random Vampire myths, and the in story explanation being that this group has spent a great deal of time falsely attributing these weaknesses to other courts, thus confusing what they are actually weak against.

Well, I did remember that instance with the Fae, but I can't really make this a direct deal, and it needs to work fairly wide scale.

A Never Never beasty of some sort could work too, but it does need to be sentient.

Baku seem interesting, but I do want to stick to memories, and the "alien" thing is a little too out their for my purposes.

My original idea was a different court of Vampires that kept their numbers artificially low so they wouldn't be easily detected, and so that their weaknesses couldn't easily be figured out, but I didn't want to just randomly come up with a new court.