One thing that could be a challenge to Charlotte imo is that it's city limits keep expanding and include suburbs. The square miles of the city are large enough to be a county. I would think if the city limits included Downtown and the surrounding neighborhoods, it would be a lot easier.
One thing I think helps cities like Dallas overcome their conservative roots is the rapid growth... As these cities grow it would seem logical that many conservative families would migrate toward the suburban counties. Also as the cities grow and garner more national attention, more "urban" type folk would gravitate there as well as minorities... Perhaps in time Mecklenburg will have a higher percentage of minorities while the conservative families would migrate more toward the suburban counties making them to Charlotte what Cobb County was to Atlanta. Kind of a self-selecting effect...
PS I'm not implying that the minority voters are more or less tolerant on gay issues, but it may help to tip the scales more democrat.
If NC's ballot access laws were easier I wonder how a libertarian or independant type or one who's pro-business, fiscally conservative, but socially moderate and gay tolerant type would do there...In other words if Charlotte can't become like Boston or SanFran or Seattle (liberal/pc) it could evolve in a more Dallas, Houston, Phoenix-like direction?
Maybe too if more of the newcomers registered to vote and minority/young people voter turnout increased it could also help...I do have to hand it to the religious right on one thing...they do vote.
As for gay tolerant churches I noticed Charlotte has about 2 Catholic Churches listed... I've never been to Charlotte on a Sunday to attend any of their several Catholic Churches but I have gone to Mass in many different parishes, in many of the states I've been to, and in Italy and have never been turned away or seen any bouncer at the entrance with a velvet rope asking me if I'm gay. While the Vatican officially condemns gay marriage, gay sex and any other sex outside of marriage it doesn't bar gay people from being Catholic or attending Mass. Not that there arent individual Catholics or Clergy that are homophobic but they can't really turn you away. In that case you could then list all the Catholic Parishes in Mecklenburg (I think there are at least 10 or so) as at least.......gay tolerant.