How to Deal with Freelancer and Staff Issues

Paying international workers, communication barriers (language), time differences, managing milestones, and deadlines. How much time should I pad? Onboarding new contractors with your process. Determining skill/culture fit? How do I vet? Should freelancers be talking to my client? How should you scope/charge for things you are not an expert in? Employee vs freelancer? Flakey freelancers. How do I distill what my client/boss wants?