As for alcohol and being lean...it depends on what you drink and, of course, how much. Spirits are typically low in calories and zero carbs, a glass of wine is moderate in both calories and carbs, beer runs the gambit from low to high in both categories. What is significantly detrimental to weight loss goals are mixers, soda, garnishes and liqueurs. They are all loaded with both calories and carbs, not to mention carbonation. If your jam is an occasional spirit neat or on the rocks it shouldn't effect your weight loss at all.
Cram, I've been in ketosis for months now and I'm pretty lean everywhere but my middle. I expect that the last 15 lbs (or so) left to lose is going to take 6 months or better. So, I'd say that Keto will help you loose your belly fat but it's not quick by itself. Combined with moderate weight lifting and core exercises you may get quicker results.
Edit: Keto's is a pretty decent sized commitment, though. I don't think anyone would be pleased with it as an on again off again sort of diet.