I'll go bottom up because this was a long post.
P2P voip can't be "masked" if you're connecting, you're either relayed and don't connect directly, or you do and there needs to be a reply-to address.
Not saving money here, saving servers and player experience, DDoSing our servers isn't going to help you and it isn't going to cost us money. (except in lost sales because people are angry) it will just hurt everyone else because people are paranoid and panicky.
Ubisoft operates on the lowest common denominator of law, because we have subsidiaries in so many countries we must follow the law of all of them, so we blanketly comply with the law. If the UK tomorrow stated that "All games have to allow people to wear yellow hats" ubisoft would release yellow hats for all it's games worldwide. (this would be required to comply with Valve too since they don't allow geographical based content).
we have regional servers, I don't know what you're referring to, your game client "pings" our datacenters and the one with the lowest latency gets chosen.
destructables /are/ client side only, the other stuff you said doesn't make any sense to me.
10 tickrate server because the game is so complicated, this is a natural consequence.. Hardware is literally the best money can buy currently (Xeon E5-2687W v3 quad socket machines w/ 256G DDR4 memory), we even eliminated the firewalls to go with stateless ACLs to bring down that 20ms layer 7 networking delay.