I doubt it, the traits that are available to the leaders of a civ are probably balanced for a particular civilization's starting picks and UU, to prevent any excessive synergy.
Being able to rename one's leaderhead and civ almost certainly will be possible at game start, and It would be nice to pick the graphic of your leaderhead, although I don't know if they will do that.
I Could see them allowing you to pick custom starting techs, UU, abilities, perhaps even favored Civics choices, BUT that would require more significant balancing than they may have done.