Bad idea. Alcohol may make the antibiotics less effective or cause serious reactions. Check with your pharmacist or doctor to know what the risks are.
Yes, in moderation. Contrary to popular beliefs, almost no antibiotics interact with alcohol. Heavy alcohol impairs the immune system's ability to fight infection, but alcohol in moderation makes no difference. The one antibiotic said to interfere is metronidazole, once thought to cause nausea and vomiting when mixed with alcohol. But that's old news (from 40+ years ago) and now known to be inaccurate.
No. When you have an infection, which is why antibiotics are prescribed, alcohol is the last thing you need. Alcohol makes it harder for the body to heal and fight infections, causing lower levels of antibodies to be produced, stopping white blood cells from ingesting and killing bacteria and viruses. In addition, there are drug-drug interacdtions with alcohol that can actually make meds dangerous.