If I'm being honest I think you're worrying too much. I'm very picky about how my devices look and perform but this is the monster Apple has created with their attention to detail, especially from a design perspective. That being said, dropping an iPhone a foot off of the floor while it's still in its box isn't going to hurt it. I can almost guarantee that it had already experienced much worse trauma than that just from the shipping process. Power outages and plugging/unplugging can cause issues on
rare occasions but, again, it's nothing to constantly worry about.
If your stuff looks good and is acting fine then don't worry about it. They're just devices and can always be replaced. Enjoy them!
