Like the Speak Easy idea a lot. My girlfriend and I tried a place called the Anvil here in Houston back when I finished my FE exam. We wanted something relaxed but fun and good.
We found out that the Anvil makes some of the best cocktails ever. I mean, they take them seriously. They are all finely crafted, shaken or stirred depending on the cocktail, and they use fresh juices and zest. It was almost like a show and a drink, watching them make it. They make one that they have to stir vigorously for
15 minutes. This was like a gourmet restaurant but for cocktails.
The place is packed every time I go in there, so I certainly think there is a market for a place like that. They also served delicious plates of food, finger food type things, but plenty good.
Anyway, thought I'd mention that so you might draw some ideas from it, if there's much to find on it on the internet. Or make the trip down...
But as far as the Speak Easy vibe and door and password, I really like those ideas. Sounds fun.