I personally think the artwork is gorgeous and I'm very happy that they chose to make original artwork instead of just sticking halfway fitting pictures on the cards as it sometimes happens with theme tarot games. Also they tried to connect the Rider Waite symbolism with characters from the show. I love that, big time. Naturally I would do a hundred things differently since everyone has a different take on the cards and their meanings and on the characters.
The whole thing got my brain turning on where I would put each character and so on. Since I have to get it out of my system, here is my personal take on the thing. I'm using my interpretation of the Rider Waite cards and characters here so please feel free to say "argh, bullshit" and comment what you think about it. I linked the wiki pages for a more objective interpretation. The more opinions, the more interesting.
I guess, Spike would be the obvious choice here. Fool for love and all. He's not exactly the wisest when his life-choices are concerned. He ignores all dangers and searches for an ideal of romance. The flower even fits with his poetry. Ever since season three, Spike had lost his place in the world and was a bit of a vagabond and searcher.
1-The Magician is usually a very omnipotent card. There are the four symbols of the minor Arcana on his desk, symbolizing that he is capable to balance all aspects of life. One of his hands is pointing up, one down, symbolizing heaven and earth, somewhat a balance between spirituality and real life. he has the infinity symbol over his head.
That's a hard one to fit into the Buffy verse. Non of them is omnipotent, they work as a group. Everyone incorporating different aspects. In the Buffy Tarot they chose Buffy as the magician, probably because she's the hero and the one who leads them. I'm not exactly happy with that choice but I can't think of something better. Giles maybe...
2-The high priestess symbolizes intuitive knowledge and spirituality. Her dress is flowing into water (usually emotion in tarot) and the moon is at her feet. I read somewhere that the scripture in her hands means secret knowledge.
I would put Drusilla on it. She fits perfectly.
On the other hand it's supposed to be a "good" card (as far as there are good and bad cards in tarot) , so if I had to pick a white hat to go on it, it would be Tara, maybe Willow.
3-The empress stands for a traditional female role model. Nurturing, beauty, bla, bla, bla (I'm not exactly a fan of the card)
Joyce would fit of course but from the vampire's perspective so would Darla. I think I'd pick Darla because she would also fit the negative aspects of the card (vane, controlling)
4-The emperor stands for Fathering, Authority, discipline, control, leadership. Another card I usually dislike (see me, totally biased, so write what you think, I'd really like to know)
Ok, I would definitely pick a villain for that card, since male authority is usually something bad in the buffyverse. Either Wilkins, Caleb or the Master. My favorite choice would be Angelus.
5- The hierophant would symbolize knowledge, tradition and organized religion.
Giles could work out, though that would not really credit the many aspects of his character. In the darker interpretation Caleb would fit.
6-The lovers: The meaning is rather obvious. the card just stands for love and most aspects of it. I used to see it more as the positive aspects of love though, with the sun on it and all. Like the working relationship, but of course it also means temptation etc.
In the Buffy tarot they chose Buffy and Angel as the lovers. They were THE big couple from the beginning but I would not put them on the card. In my interpretation all of Buffy's relationships are too angsty to fit the card. I would put Willow and Tara on it, since they had the happiest romance on the show.
7-The Chariot: Victory, Pride, Success
I don't really know what to do with the card. Buffy is a bit about the underdogs not about the traditional winner. After a bit of thinking, I'd say Riley would fit. He has that sunnyboy thing going for him.
8-Strength: It's inner strength mostly. The card has woman on it, petting a lion. She like the magician has the infinity symbol over her had.
That card is made for Buffy. Strong, protective but also good and with a lot of self control. One could draw a pylean vampire as the lion.
ETA: continued here