Virus.
Large in comparison to a sd card.
Files may get corrupted.
Storage space is limited.
yes but usb 2.0 devices dont work on usb 1x
usb 2.0 can support 127 devices
Any USB devices as long as the computer has USB Ports. Plugging new USB devices in old computers (older than 3-5 years) might not work as newer devices might use a newer USB version. Generally this rarely happens, I never had an issue of a USB device not working on a computer with USB.
backward compatible
no they are storage device
The advantages of a USB SD are that you can store information. The disadvantages of USB SD card reader is that it can be lost easy.
All the devices properly installed on your computer will be listed. Some USB devices will be not explicitly listed, but the USB port will be.
In theory a single hub of USB can support 127 devices. In practice, this will not actually occur. Most computers do not have enough power to drive that many devices. A reasonable number would be about 20.
Buy a USB extension plug in.
Cardboard
This is not a backup drive, its a USB hub. Its designed to add more USB ports when you do not have enough for all of your devices.
Yes they do make car stereos with USB. Double check that the USB will read memory cards or flash drives and that the USB is not just for mp3 devices instead of storage devices.