Can I use the chicken marinade to baste the chicken?
After raw chicken has marinated in any kind of liquid, that liquid is as unsafe to consume as raw chicken is. However, you can baste the chicken very early in the cooking process, because the marinade will get cooked through along with the chicken.
To use the marinade later in the cooking process or as a sauce, you must boil it vigorously for at least 1 full minute (and to be safe, I prefer to boil it for two minutes). Then use a CLEAN basting spoon or brush to apply it to the chicken.