Yup, as shown, having only CT1 on the circuit will miss this load, while the meter, monitoring both sides, will catch it. You’d need CT2 in order to get a complete reading. And while circuits will be staggered so that they roughly balance out, if a constant load, which is what will have the greatest effect on the bill, happens to be on the side the CT isn’t, you’ll miss that usage.
Regarding #2, you could get a European adapter and wire up a 240V circuit for it easily enough.
Regarding #1, yeah, there’s often a few volts difference between the two legs depending on load, and that can introduce inaccuracies. In my particular case, since I’m using multiple emonTx devices in even quantities, I can have them monitor separate legs of the service and hand them voltages from those specific legs.
Durpity, how did I accidentally delete the post?