Are there any dedicated Record Stores left in the US...

I misappropriated the term "program block" from radio, but didn't mean it in that sense of the word, no FCC involved. My sense is that the store can't survive if just a fixed form thing, trying to appeal to all people, at all times. And I would imagine you're trying to make it the hot place to be, a destination, the talk of the town. Not exactly velvet ropes at the door, and people lined up for blocks to get in.....But how could a little of that hurt?

Obviously, the primary objective is to set up a record store. But in order to survive, and draw in a broad base of clientele, I envision something much more varied, (and frankly labor intensive), but possibly enjoyable to the owner. Part nightclub, part 50's dance hall, part"step right up and be the DJ for an hour", etc, etc.

You can't do all of those things, all of the time; So you do some of those things, some of the time.

You have "the store" pretty much exactly as you dream it, existing in that configuration during nearly all business hours. But during certain windows of time, on a predictable schedule, (but always subject to change), "the store" transforms for a few hours into a Jazz club, to keep Lunatic 59 and his friends coming back, eager to tell their friends, and wondering what you might try next month. Shove all those display cases into the corner, put out a half dozen tables and lounge chairs, and let them dig it, for those two hours of the program block on a Wednesday night. Scotch, cigars, and Charlie Parker.
I'm guessing the same people won't be showing up for "Heavy metal karaoke Thursdays", but if everyone has fun on their target night, they might look a little harder at other nights (or days) on the calendar, mention some of the other cool things going on there.

And it needn't be something that transforms the entire store for that time period. Twice a week the Kiddie Corner" gets set up while regular business is ongoing. All the cool parents have figured out you know your stuff, they bring in little Jimmy and Janie to be entertained, educated, in a safe environment. "Gee, Jimmy, if you like that, you should try this......It was a big hit when your parents were about your age, you should definitely hear this.
Get to them early, customer for life.

In truth, I have no real interest in spending much time in any of the places I have described. And I can think of 1,000 business complications with my fantasy. While I am perhaps the least gregarious person you will ever meet, I sometimes relish the idea of being the tophat and tails wearin' ringleader of the big 'ol circus, entertaining all my crazy friends, with the show that never ends.
The carnival barker, peddling cheap thrills.
It could be fun, and might actually be the revenue generating arm of the business that supplements the thing you are really trying to achieve.
Profit margins on records may be low. Profit margins on the accessories could be much higher. The T-shirts with your logo on them, the Rolling Stones mousepad impulse buy, and certainly the booze. During (certain windows of time in the program block), the scotch is what brings in the revenue, loosens a guy up enough to buy an expensive cigar marked up 4X retail. And maybe even a "Tubes" refrigerator magnet.