I think looking at these as relaunches is wrong. I'm thinking about them as seasons of a TV show. Like, here's 12 months to tell this story that's with this character from this creator. And then they all turn over with new #1s to tell the next story. I like it. Makes it easy.
The Builders die too easy thing isn't a big deal at all. Just the usual "technology looks like magic" sort of thing. They were in ships, flanked by incredible robots and shielded the whole time. The individual Builder was never portrayed like a god - their technology was.
I really like that this in NOW WAY changed Tony's origin, but just provided some interesting flavor to his family and introduced new characters. But there's not one single tiny change in the reality of how Tony grew up and became who he is now. I'm a huge fan of stories like this.