Trying to answer as best I can: Your culture won't smell like alcohol and it won't smell like bread yeast. It will have it's own unique sourdough smell.
Yeast gives off alcohol as part of the process. Different yeasts have different tolerances for how much alcohol they can stand. Basically once the alcohol gets to a certain concentration, the yeast will go dormant. Similar mechanics with beer.
The fact that your cultures doubled is good news. But remember, once the yeast exhausts the available sugars in the flour, they will stop bubbling. That's normal.
If you are leaving your cultures out at room temp, you'll exhaust those sugars quickly.
When I refresh my culture, I leave it out on the counter until it's bubbling and has almost overflowed the container. At that point it goes into the fridge. I will leave it there up to a month before doing another refresh.
Hard to explain but your culture should have a sourdough smell. I can't think of anything to compare it to. Using supermarket sourdough for this may be an exercise in futility as those breads can be pretty lame. My guess is there's nothing wrong with yours.
The only thing I can think that's different from what I do is leaving it out at room temp for more than half a day.
You can abuse sourdough starter up to a point but once you say you're sorry it's your friend again.
Time to make some bread?!
Looking at that picture you did definitely get a rise, in fact you got some big air holes. I would be happy to get that crumb, and I have baked plenty of bread. From the shape of it I suspect that what happened is that it simply spread out on you, rather than going up, which is common with dough that has a high hydration level like yours seems to be.
Bread dough is a bit like water in that it will flow the path of least resistance, if you simply plop a dough down without restricting it or shaping it you'll get a spread. Shaping will help depending on the result you are looking for, but I would recommend you use a shaping basket, also known as a proofing basket when you do your final rise.
Best Answer
It depends on the temperature of your room, but you may still have enough left alive to save it. Is it still bubbling at all? You should throw most of it away and feed it and see if it changes and bubbles in the next few hours. I'd try keeping just a few tablespoons (maybe 100g of the starter, throwing the rest away) and add 500g of flour and 500g of 75°F water. If your flour is precious right now, you can use 250g and 250g instead.
You probably know this, but keep it in the fridge in the future if you're not going to be able to feed it for a while. Depending on the type of starter it can do well for a couple of weeks.