Its not normal for scales to be missing but maybe they are shriveled up from mites. Mites will cause scales to shrivel sporadically. Its normal for them to hid under the substrate. They want to be completely out of view thats why your snake is choosing that over his hide away. It will be different down the road. Are you sure the cage is not only heated but heated properly? Is there a drastic change in temperature from day to night in the room the cage is in? Baby kings don't normally regurge, so it might be the temps that caused that. 70-85 is a good range in temps for them. Good luck.
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