You really need me to argue that achieving 100% uptime and trust (not 99.99%! 100% was the claim) just by virtue of building on top of Ethereum is implausible?

As long as there is one node on the network that you have a route over the internet to, the network is up. This is why bitcoin has also never gone down thus far.

I believe he was interested in hearing the details of the bridge deal.

Yes, explain yourself please.

You can trust it in the sense that the network will execute the code you run on it, for the most part, but most of the contract code out there is full of bugs and they keep forking the chain when people fuck up if they know the right people.