I can play 7/7/7 thanks to the double Traveler's Amulets and with the green fixing that would be more like 10/10/7 (with double green being easy to come by for the Sifter Wurm as well). I want more green since that provides fixing, but the problem is that my early plays (other than Traveler's Amulets) are all black and white.
There are also a few cards that I could see swapping in and out. For example, I put in the Binding Mummy because it works well with Accursed Horde and Unraveling Mummy (which in turn works well with Crested Sunmare). Is that enough? Even more borderline is Sacred Cat, which has some of the same synergies, but is only a 1/1 and doesn't have the same ability as the Binding Mummy for tapping things down. I've also heard that Torment of Scarabs is decent in sealed because of the longer games, but I've played against it multiple times and while it's been a headache a couple of times I don't think I've "lost" to it yet. But, is something like Rhonas' Stalwart any better?
I'll probably also try building an aggressive RU deck just to see how it looks, but I can't see leaving Angel of Sanctions, Crested Sunmare (with good support), Sifter Wurm, Grind to Dust, and Never to Return on the sidelines. I'm pretty sure that there's no situation where that's the correct move for a starting build and even when sideboarding against a known deck it has to be pretty rare that it would be correct.