I don't think they are related.
scrambled file name is a "feature". It permits to have several files with the same name and is better for security. Tiki handles the conversion. There has been talk to have an option to use existing file names & directories but no code yet.
I don't see why you couldn't upload jpg files. You could also use image gallery.
Can you try version 3 (in Beta) and see if the jpgs work for you?