1. Is the practioner supposed to abstain from "bad" things in the evening after breaking the fast or is it just during the day? What's the hardline, "accepted", and commonly practices answer to this? 2. Is the big dinner party thing on the last day of fasting or the subsequent day? 3. Do people get gifts, when?
2- Big dinners are everyday at sunset. Some people/cultures have several meals before dawn, some other prefer to have just one or two.
3- Nobody get gifts. Usually, it's kids who get new clothes during Eid and they also get money gifted to them (usually small change and can range between $1 and $20 depending where you are). During Eid its required to visit family and friend in their home.