Q1: How long of a cable can I use to connect my device?
A1: In practice, the USB specification limits the length of a cable between full speed devices to 5 meters (a little under 16 feet 5 inches). For a low speed device the limit is 3 meters (9 feet 10 inches).
So if your's is a USB webcam then this could be one limitation. And webcams are generally low speed devices. So for sure it can't be greater than 3 meters.