Garp probably moved him for fear his location would become discovered and his connections exploited before he's 'safe' in the marines.

Ah, you mean because Luffy would probably talk a lot about how great Shanks and his men are, to any passing stranger willing to listen? Yeah, I guess that could attract the wrong kind of attention, if they're unlucky...

I wouldn't hang onto the whole Usopp thing. I just don't like the idea of 'my tragedy is more awful than yours' oneupmanship anyway.

I don't, either, but lots of fans seem to engage in it, alas. But it's mostly just an over-defensive fangirly reaction of mine.

It's more about the wounds on the heart than whatever actually happens in their past.

That's very well put.