You really cannot drag a obsolete system into being a current system. Linux is built in a modular way. Each major component depends on a lot of other major components. You cannot replace them one at a time, you have to replace them all together. An easy example is trying to update the gcc compiler. Since EVERYTHING in the system is built around that particular version of GCC it is virtually impossible to do.
Even if you update rpm you will NOT be able to run rpms that have been created for newer systems.