Man, I wish I still had my DX6i. I had mine flying pretty well. I think I did a throttle curve of about 0 45 75 75 75 and a pitch curve of 46 48 50 75 100. Set your DR at 70% and your expo at +35 on aileron and elevator. Don't touch the tail.
However with that said, the mcpx is twitchy on it's good day. So taming it down is probably not going to happen to your liking for indoor flight. For something like that, check out the msr. Very simple to fly and great for inside the house. I have bounced mine off the walls and just picked it up and went again.