1. Are the team actually working each day (many people need the discipline of coming into the office) 2. Are they moonlighting with multiple companies at the same time 3. How do you get a sense that you are really part of one team, a feeling of connection 4. Communication issues related to working remotely 5. Hiring effectively without actually meeting in person 6. Maintaining a sense of team and having people feel like they are part of a team (even when not meeting in person). This is very important as part of maintaining a sense of loyalty and connection with team members.
My personal experience in managing over 50 staff members in 9 countries is that all of these problems CAN be solved, but it takes work. My ideal situation is to meet 4 times per year in person, but sometimes this is difficult when staff are really in completely different locations.