Question about Icy Box Raidsonic IB-AC6104 4 new USB 3.0 devices

Hello raphicorrodi
Yes, that is exactly how it is. You only need the 5V power supply when you connect things that need a lot of power (like an HDD). But the power supply is a standard connection. You might even have an old one at home (e.g. from an old router or something). Mice, keyboards and sticks should not be a problem.
You can also connect your mobile phone to a port. It probably won't drain much when you use it, but it will charge very slowly. It would certainly work better with a power supply unit.