So, is it possible if I ask for much of 子女生活費 to maintain the current living standard and no 膽養費?
May I ask for an increase of these amount if the income of c6 increases?
You can ask for more if he has increment of his income later after the amount has been settled. As well as when your child getting older and the child expense is getting more (for example : need more on food or for education).
It is NOT advisable to ask for nothing for 膽養費, lawyer usually advise you to have at least $1. Therefore, you can ask for 膽養費 for yourself if your c6 all of a sudden become a rich man later.
Good luck.
p.s. I think the first word of "膽養費" is wrong. I just cut and paste cause I don't know how to type Chinese. Sorry!