sorry for picking such an old thread, but I just tried creating a ROM for my S3 mini VE (GT-I8200n). I followed your tutorial step by step, just deleted some of the stock apps instead of rooting, but while flashing with Odin (v10.6) it says "FAIL!" shortly after starting to flash system.img. I also tried just to unpack and repack system.img without changing anything, but still get the same problem. Is there anything i am missing? Or does flashing only work with an specific version of Odin?
P.S.: just noticed that the repacked system.img is slightly bigger than the original one (about 9 megabyte), although I didn't change anything. Could that be the problem?