Okay -- here's some comment from one of the inspectors that tells you about drilling for safety wires. Remember, though -- these are my personal comments, not necessarily what the sanctioning organisation might say.
First of all -- yes, we've considered whether drilling the fork leg might weaken it. To that end we now often suggest that instead of drilling the fork leg itself -- that you take advantage of the fact that a good many forks have a hole in the bottom of the leg. Drill the bolts and run the safety wire through the bolt heads and through the hole already in the fork leg. You'll have secured the bolts without affecting the leg.
If you can do it that way -- you'll pass tech and not make your friends worry for you.
