I don't know, it seems like this idea is more flawed than we think it is.

Just because we're able to cast Pride in a better light doesn't mean the same thing for any of the others. Just to list them out, here they are:

1. Pride: Already covered
2. Greed: Unless it's greed for knowledge or, in Fullmetal Alchemist's case, friendship, I don't see it working.
3. Envy: Pretty much just the same damn thing as Greed.
4. Lust: Lusting for power, fine, I guess. Doesn't mean you can make it sound like a good thing.
5. Sloth: Yeah this one is just... eh.
6. Wrath: Doable, if you're talking about a revenge-driven character. But that's about it.
7. Gluttony: You seriously think you make this a good thing? Good luck with that.

And as I already said, I just don't think any of these fits Daigo at all.