Post op regimens will vary. Most will recommend support in the early peri-operative period. Daytime use is more important than evening use. However, many will recommend 2-3 weeks of around the clock usage.Ultimately, gravity is undefeated. The more external support given the less effect gravity...
It is hard to give an opinion without seeing pictures. The area may be more noticeable after breast reduction surgery, so if you can afford it you may be happier with your results. On the other hand, does it bother you now? If it doesn't perhaps you don't need it. It might be wise to get another...
Unfortunately, each insurance company has their own criteria. Large breasts (macromastia) or breast hypertrophy can occur in a variety of conditions (family trait, post pregnancy, excessive adolescent growth). In general when the excessive breast size causes functional problems, insurance will ...