The men unleash the brutal side and battle it out to win their lady love.
Here 'it' does not refer to 'brutal side'.Am I right?
It is difficult to root for the characters even as the actors score.Tiger's back flips may make you cheer and his stunts have gotten dishier since Heropanti, but that's about it.
'Even when' is clear to me but I am unsure of 'even as'. In 'that's about it' , what is 'it' referred to?
Responding to your first question, yes, you are right. It does not refer to 'brutal side', rather battle it out is a phrase which means to compete with each other until there is a clear winner.
Coming to your second question, the word 'even' is used to add a shock factor to the statement. "Even as" is used to refer to two actions which are going on at the same time. In the given statement, "even though" seems like the most appropriate phrase to use, even though the other two phrases can be used as well.
Now on to your final question. 'That's about it' is a phrase used to stress upon the fact that there is not much apart from the above mentioned fact. 'That's it' is a good alternative as well. The phrase, when extended, means 'that's the end of it'. So 'it' here would refer to the achievements of the actor.
