> I mean generally I want fixed IPs on my local network for robustness.
What do you mean by robustness? Isn't it really stable hostnames that you want? I don't understand how fixed IPs increase resilience (to what?).
> I'm hesitant to turn it on on my local network because it does make my firewalling concerns much more critical.
Block everything coming in from outside the network. Allow established connections. That's all there is to it.
You're assuming there is only one internet connection in my home network, for example. The "easy" trick where your ISP gives you routable addresses does not work when there's more than one exit.
Still want to help? :)
And really... everyone is pushing for SSL everywhere - among other things so that the ISP doesn't MITM your traffic.
Why would you allow the ISP to know what machines are inside your home network then?