I seriously doubt you will ruin your crankshaft even with a balancer that wasnt mad for your car on there. If you see it vibrating more than you like just shut the car off and take your balancer off and have a shop inspect it to make sure its true. If it is then you have more issues with your engine then you would hope to have
I have cracked balancers and drove home around 2 miles from where it happened and it did not ruin anything (but then again probably one of my lucky moments).
Just get a new balancer and put it on there