1. I don't think you'd want to try drilling with the balancer installed. The drill guide wouldn't fit on the nose of the crank and you likely would get the hole mis-aligned. Although you could fabricate a drill guide that inserted into the balancer instead of over the crank snout.
2. It's not advisable to use the bolt to install the balancer, as it's likely to strip or damage the threads in the crank. The proper way is to use an installer that threads into the crank (keeping those threads stationary) and pushes the balancer on.
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