We do not currently have the ability to designate an alternate location to store photos on the Mac. This has been suggested and we are looking into this for a future versoin as we realize that many of the newer macs only have flash memory and that it is limited. If you are runnign out of space, you can disable save originals and use an external hard drive to back up photos from your computer and other devices manually for now. I wish I had a better solution for you currently.
I am not aware of any techer or student version of revel, just a free version and a subscription version.