Mini-bics are 11 grams when full. I should deplete one and reweigh it, but haven't used one up yet. EVERYTHING with fuel in it (butane, propane, bics, etc) gets weighed when it comes into my house full and that weight is recorded on it in laundry marker, "full = 11 g". Then, I reweigh when empty and record that on the container, "empty = X g" or "tare = 15.9 oz" (for a propane cylinder).
A flint will give you a hot, burning bit of flint, metal, magnesium, whatever, which I'd estimate to be at about 2300F. That's enough to light a lot of things, maybe anything IF the conditions are just right. But a flame is hotter AND has very short-lived, very energentic species that don't normally exist. Those high-energy species transfer a lot of energy and are one of the ways that a flame front propagates. All of which is to say, it doesn't surprise me that a mini bic is far better than a flint at lighting a dodgy fuel.
Why do I call alcohol a dodgy fuel? The flashpoint of pure ethanol is about 55F - the temperature at which potentially flammable vapors can exist above the liquid fuel. Sparks add little heat and so you're pooched on a cold morning. Gasoline, by comparison has a flash point of -50F which I've been close to, but never below. But a mini-bic will obviously raise the temperature of the liquid and especially the vapors to a point where it can ignite.
In a pinch, you could scrap metal filings on a piece of paper or toilet paper, light it, and then use the burning paper to light the alcohol.