Look, I don't know how much screen time Amanda will have but let's be honest, I really don't think that her character and/or how she is portrayed and/or acted will have much chance of making or breaking this film. There are many more important variables the movie will have to contend with.
As for Ms. Horowitz (her real name), I have zero issue with her as an actress. She's easy on the eyes (at the very least (I had a little crush after Heathers came out)) and I'm sure she'll do the role justice.
"Stop it? I'm counting on it."
"But not because you threaten me. I'll pay you because... it's my pleasure."