I'm sure others may have thoughts about the handle finish - but I wouldn't worry too much about the handle being food-safe. Normally, the blade is the main thing that comes in contact with the food.
As far as the scales are concerned, my main worry would be water infiltration of the wood and the harboring of bacteria. The best way to address this is to make the scales as close to "waterproof" as possible - this way you can wipe them down and sanitize them after use.
And the best product I've found for making knife scales waterproof is Tru-Oil, which is sold in sporting goods stores as a gun stock finish. Tru-Oil is a polymerized linseed oil base which cures hard and waterproof. Just make sure to put on very thin coats, wipe it down, let it dry, buff it with steel wool, and repeat. I've used it for years - and on a recent mule (see the pictures of the Purpleheart Swick above), I put on 8 thin coats over a couple of days. It sealed the pores and made a clear, hard, impervious finish. Great stuff!