hi there 
im planning to buy a rytm, but in the meantime i have chance to get my hands on another rytm, play around with it, fill it up with samples and try to make it as versatile for my kind of music as possible. but when i get my own rytm then, is it possible to copy all projects and samples from one rytm to another, or do i have to start all over again?
When you use the borrowed AR, you can backup the kits, sounds, patterns, songs and global data to a computer or to another AR. Read the “SysEx dump” section of the manual. This does NOT include the samples, so you should keep a separate backup of those.
You will need to keep careful note of all the information in order to restore it fully.