Some may stone me for this, but could Ady replace the Tatooine matte at the start with something new... Was watching a ANH:R last night, and the planet surface just looks like a painting to be frank, it too mono layered rather than looking 3D despite Ady causing it to slowly spin.
The other suggestion, again some of you may not like, is having a different Death Star explosion... The original explosion just doesn't seem very realistic to me, there's very little debry just some yellow particles.
Possible other suggestions, though not sure where they could fit in pacing wise would be brief cameo's for the Emperor and Yoda; possibly have the Emperor appear briefly as a hologram fading out to say Tarkin, Yoda, could react along with Ben to the destruction of Alderaan.