I do not understand why matching resistances is so important in rf applications. Why not just consider each function as a module and give it high Rin and low Rout? By function, I mean such systems as an audio amp, an if amp, an rf amp. I'll sure appreciate your input. Also, I worked briefly for a company that made frequency synthesizers. We used dBm there. Why not dB? Why not gain expressed in V/V?