I think Columbia Heights could do well. There is already a sizable gay population in Columbia Heights and no gay bar. I also think H Street is intriguing, but probably a gamble given that gay people don’t really live in large numbers in that area. Shaw is perhaps safest, as it has a large gay population and it’s near Nellie’s and Town. I agree that something near Secrets could really do well. There’s nothing near there for pre-drinks.
The real key is how you’re going to stand out. People like to go out to bars that are near other bars. This way, there’s no trouble hopping to another bar to see friends. People enjoying jumping around from bar to bar. So, if your bar is in one of the neighborhoods you’ve listed, and presumably all alone, without alternate bars, what is the draw? I’m not saying it couldn’t be successful, but you would really need to put in some thought as to WHAT the pull is. What is setting this place apart and luring customers in?