Only once, once it is thawed you can not refreeze it.
It isn't generally safe to refreeze raw food. This is especially true for chicken, which is contaminated with salmonella at scary-high rates. If the chicken has thawed, it isn't generally safe to refreeze it and eat it later. This is especially true if it is thawed in room-temperature water rather than being thawed in the refrigerator. Once thawed, the chicken should be cooked fairly quickly. Once cooked, it can then be frozen for later consumption.
Chicken should be used within a couple days of thawing.
Once a food is thaws it should be used within four hours. It may keep for an additional 2-3 days if it is refrigerated.
It is not recommended to re-freeze ANY type of food product once it has been thawed.
Yes. It is preferable over trying to refreeze raw thawed chicken.
Normally, frozen vegetables are not thawed first but are cooked from frozen.
Depends on what temperature the chicken got to before "refreezing". Once it gets over 40F it should be cooked or discarded.
Rapid thaw methods should only be used if the chicken is going to be cooked immediately after thawing. By not thawing it in the refrigerator, you have temperature-abused the chicken. There is no way to know how much more quickly the chicken will go bad.
24 hrs
Once opened, it should be refrigerated. Then it can last 2-3 months.
Once Chicken/Turkey has thawed it is OK to re-freeze it if it has thawed and the ambient temperature of the bird has not risen above 40 deg for more than 3 hours. Because freezing causes ice crystals which damage the meat each time, repetitive freezing will result in poor texture.