Nice! I think I saw a different figure of that line last night while browsing for Akira figures... those ones aren't cheap!
I definitely unbox and arrange my figures. No point in keeping them boxed unless you want to sell them later or keep them for the purpose of just having then IMO ^_^
woahh for how old it is, the quality and detail on it looks super good ! i think it's more fun to take it out of the box and display it on its own, but if you want to display him still in it, that would also work. i tend to flatten and hoard the boxes from my figures bc the packaging is pretty, which you could probably do if you still want to preserve it. i'm sure there's a way to separate the plastic from it without damaging the cardboard.