eventually also ForgeEnergy and Tesla (if no other mod already provides it)

I have to close this.
As it stands right now, the AE2 API does not support custom P2P tunnels.
Either AE2 adds those themselves (which I don't think is necessary due to most RF mods being compatible with ForgeEnergy (FE) as well) or AE2 changes its API to allow P2P customization.