All those powers are justifiable on a fictional level of understanding. Added to that, each fiction has its own logic that has its based storytelling. Obito traveling through Kamui dimension to escape or defy death is ridiculous and pretty asspulish, even when you put it next to blowing up moon or creating Bijuus. Given your response, I doubt you understand what I'm saying so don't drag this any further, for your sake.
Also, to correct you, you do need to have an Uchiha body for Sharingan to operate properly, according to Itachi.
