Is it ok to save other files in the Unity? We use the Unity to store the BPAV files of the sony EX camera and view them through the EX clip browser over the network. Is that ok? Or does it affect the performance of the Unity?

We use Unity workspaces to store everything from After Effects and Flash project files to Word docs and PDFs, as long as it's connected to a particular project of course.  I prefer to have everything together and it makes backup easier. I've also got a small workspace where we store fonts and even some FLV tutorials on some of the apps that we use.  In emergencies we've even kept P2 data in a workspace as temporary backup until it could be dumped to a USB drive later. I've never had any performance issues working this way. Just keep in mind that there's no Recycle Bin or Trash if you delete something by mistake! I always remind my people to keep offline copies of everything they work on.