Nah, I would definitely do well without those murals. Eugh, lol. I think that the backstory revolves around Gru stealing the soundstage, preparing it, replacing it, and then installing his home there to make his venture for acquiring more minions (i.e. us) a reality. Hilarity ensues?
Also, I think it would look cool if the soundstage was decorated along the base to make it truly seem as if Gru took it with him and planted it back.