If the branches hit another jutsu, they will only do 80 or 100 damage regardless of how many land BUT if they bite a target, each bite will deal more damage. It's similar to Nekura jutsu and how the inherent damage boosts only factor in when they hit the target and not in clashes.
Ninjutsu, Genjutsu and Taijutsu are all applications of Yin-Yang; Ninjutsu is created through different ratios of Yin to Yang energy, and off Tai and Gen are almost exclusively Yang and Yin, respectively. While this is in use, you cannot use any ability that is based on some YY usage. Elemental Ninjutsu, however, is the result of shape and nature manipulation of raw chakra and doesn't require Yin and Yang usage, which is why it can be used. Basically, only Elemental Nin + the advanced version of this is all that can be used. Understand now? I explained badly before
Ninjutsu, Genjutsu and Taijutsu are all applications of Yin-Yang; Ninjutsu is created through different ratios of Yin to Yang energy, and off Tai and Gen are almost exclusively Yang and Yin, respectively. While this is in use, you cannot use any ability that is based on some YY usage. Elemental Ninjutsu, however, is the result of shape and nature manipulation of raw chakra and doesn't require Yin and Yang usage, which is why it can be used. Basically, only Elemental Nin + the advanced version of this is all that can be used. Understand now? I explained badly before