I don't think it's necessarily a case of anyone not allowing their likeness to be used, and more that they only wanted to have 16 character decks (the same as with the Marvel game), and with 4 different Ripleys, that leaves only 3 other slots per movie.
I had no trouble with the rules as written, but I've also played the Marvel game extensively.
The art...I feel you. It's a definite stylistic choice, though, and I like that it seems to be fairly consistent. I also like that it is actual art rather than photos. That said, though, I'd definitely rather art more in the style of Dorman/Beauvais/Bolton, or any of the other classic Alien artists.
Sent from my SAMSUNG-SGH-I337 using Tapatalk 2