1, 2. We're working on it. Should be available in 2 workweeks.
3. DirectCapture formats that capture video without reencoding can decrease CPU usage (near 0-3% CPU will be required, it's a simple copy and remux operation). Or, you can use reencoding with GPU video encoders instead of CPU usage.
4. Our SDK contains some basic features like facial recognition and pedestrian/car counting.