Well, によって the book nothing will happen if they eat something, in Twilight Edward took a bite of ピザ if i remember well, so maybe it's not a flaw in a movie, they just tried to 表示する how r they tryin to blend in with humans...
Well, there's a possibility that his car is adjusted for ppl who can't walk, all of the operations are hand controlled, in my country there are loads of cars like that, I've seen those...
Yes I agree with Bella0405...disabled people can drive...the brake and the gas peddles are turned into hand controls that up close to the steering wheel..my uncle ロスト his legs years 前 and still drives to this day...:)