You absolutely can. RotaryCraft is mechanical power. Just like machines in real life, once you've moved from shaft power to electricity, it's all electrons.
Fundamentally - AC, DC, doesn't matter - it's all a count of electrons. Yes, you can model it with differential equations, synchrophasors, V=IR, V=I*Z, however you like. But this is Minecraft and we need something Minecrafty and server friendly.
That's RF. And it lets us move energy between tiles. But you can do other things with it. TE dynamos have a torque-speed curve. TE machines likewise scale speed based on available energy. These features emulate some fairly advanced mechanics found in real power systems. You can do a LOT with RF.
And, you're under no obligation to use it. The community probably shouldn't push people to adopt it, but at the same time, having a standard that all mods can interact with is a good thing. That's part of the sandbox glory that is modded Minecraft.