I cross that border quite a bit, it is only 10 minutes from my house. They may be a bit stricter if you have out of state license plates, but have your ID anyway. They do random check of cars etc. Make sure you tell them you are going to the casino, they are nicer because they want the american dollar.
As far as other casinos, you can go 2 1/2 more hours and go to turningston or go to detroit, it depends where you are staying. Detroit is only about 3 hours (through canada) from casino niagara.