"50/50" -- instead of 49/51 or 51/49 -- just automatically NEGATES 2/3 of alimony and 1/2 of child support??? That doesn't sound right to me. In fact, in sounds insane.
If that's the case, then refuse the offer. Personally, I think you should now dramatically up the ante and go for FULL CUSTODY, and staying in your home. You are clearly the better (only??) parent here, SP, and it's time to put the legal boot on your wife's throat, IMHO.