On consideration of spousal income, see the answer to that question I posted today on this site (if you don't see it, let me know).
The question on time share and abatements is that abatements are disfavored, even during extended summer visitation, but if the total time share is 60/40 or closer, looked at over a whole year, you may fit under the revised opinion in the Rivero case for what constitutes "joint custody." For details, see http://willicklawgroup.com/child-support/.
As to the third child, you could ask of course -- but the likely response wold be to send the child somewhere else.
Nevada courts do have the power to allocate tax exemptions, but generally the question is which parent is providing more than 50% of total case for the child. In lots of cases, it makes sense to divide the exemptions when there is more than one child.
Answered on Mar 14th, 2013 at 12:59 PM