I have told about the needed features countless times already, but I'll repeat myself again, what I see that needs fixing but isn't adressed with bitcoin: a) Speed of increasing wealth concentration b) Deflationary system that prohibits price stability c) Inefficiency of mining where new resources are spent while the network doesn't gain in speed or security.
I recommend many of the Alt coins that address your concerns specifically, if they truly are better, you'll make a killing.