Your kids won't be this young forever. The decisions you are making now will stay with you for a long time. Even if it's difficult to make it so that you can have an equal number of days and nights now, eventually they will be able to be by themselves should you get a call.
In my opinion, there is no more important/significant settlement issue than custody/visitation, and all it's surrounding issues. Summer vacations, holidays, birthdays, decisions on things like camps, sports to play or not play. Given your wife's refusal to co-parent so far, all the more important that as much of these things as possible be well defined in your agreement.
Blessings,
Bill
"Don't tell me the sky is the limit when there are footprints on the moon."
