I would not go into mediation with ANYTHING being non-negotiable. I would have a list of things that you want, of course, but don't make anything non-negotiable.
My experience is that the lawyers/mediator will have ideas on ways to settle that you have not considered. For example, I was at mediation last week and the mediator suggested that I could pay xWW a settlement from my retirement rather than in cash. That would have made settling easier if we were closer to a settlement.
I have some comments on your ideas... please note that I don't know where you live and I am not a lawyer, so a better answer might depend on the legalities in your location.
* custody will be 60/40-- he works 6 days on 4 days off
* Standard child support in my state is 20% for 1st child and 5% for each additional child. I will be asking for 20% child support
* He will insure kids for medical, vision, and dental.
* He will pay 80% of all medical bills
* He will be responsible for purchasing the kids their 1st vehicles
* He will be responsible for maintaining said vehicles
* He will pay for the kids car insurance on the kids vehicles
* He will pay the kids phone bills
* Kids are involved in extra curriculars that are pretty expensive. He will pay 80% of the costs incurred by these activities. I will pay 20% up to $1000 for each child in a years time.
* Any extra curriculars the kids are involved in prior to divorce will be paid by him
In my location, child support is based on your incomes and how many nights the kids spend at each parents house.
Generally speaking, your financial responsibility depends on how much you make versus how much he makes. You say that he makes about double what you make, which means he makes 2/3 of your combined income and you make 1/3. That is, with even custody, you could expect to pay for 1/3 of the kids' expenses and he would pay 2/3. This would include everything, including insurance, cell phones, and activities. You seem to be asking for him to pay way more than 2/3 of your kids' expenses.
Be particularly careful when it comes to medical insurance for the kids because these can vary widely depending on insurance plans. My GF pays for insurance for her kids and it's something like $600 per month out-of-pocket, so the majority of the child support that her ex pays isn't really "child support" so much as it is his share of their medical insurance. You also need to negotiate who pays for uninsured medical costs.
You should also negotiate the child tax exemptions. You should be specific... you split them until the first child emancipates and then you alternate the other child until he/she emancipates.
Please also note that if your ex wants to fight for custody different than what you propose... that your kids are of an age where their opinion counts for a lot.
* Retirement accounts will be divided 50/50
Assets/liabilities are usually split 50/50 in total and I would definitely stick to that. My ex tried to manipulate values of everything to be biased towards her (the stuff that she wanted had little value; the stuff that I wanted had a lot of value); beware of this trick and don't be afraid to ask for independent valuations of important assets/liabilities. The values of things like cars, boats, etc., can usually be determined by resources that your lawyer should already know about.
* not alcohol or drugs at any time while the kids are present.
My GF used the language of "no alcohol consumption to intoxication" with her ex, who is currently an out-of-control alcoholic. Also remember that there really isn't a parenting plan police, so enforcement will be difficult.
* Neither of us can introduce a new BF or GF to the children or have them sleep over while children are in our custody
This seems a little too restrictive. What if either of you wants to get married in the next six years? I would suggest that you come up with a slightly more flexible plan.
* Neither of us can tell the kids that BF GF will be their new mom/dad
This seems to be unnecessary but I can't imagine my kids calling my GF "mom". In fact, I wouldn't allow it. But if you think this is pertinent... by all means...
* Who ever is picking up must drive to the other parents house
Yes! This is important!
Along these lines, you need to set times and days for pick-ups.
Also, you need to think about holidays (which ones?). My xWW have only the following holidays: Mother's Day, Father's Day, Christmas, Thanksgiving, Labor Day weekend, and Memorial Day weekend. You could also include other holidays, like Independence Day, President's Day, your birthday, his birthday, etc.
My other suggestion on this is to have the pick-up times consistent. The pick-up times in my agreement are inconsistent and it gets confusing. On a regular day, she picks up the kids on Friday at 8am. But, if it's a holiday, she picks the kids at 9am.
You might also want to be clear about who and how the kids are getting to school. My agreement was kind of unclear.
* Vacations/trips must be discussed and agreed upon prior: 14 day for in state trips and 30 days for out of state/country trips.
My agreement allows two non-consecutive weeks of vacation each summer (and *only* summer). There is no need for agreement between us because it's a first-come, first-serve situation. I agree that permission should be required for taking the kids out of the country.
* Kids will stay in current school system until graduation
If you have primary custody, I would say that kids go to school where you are.
You need to be careful about preventing you from moving if you want in the future. You have 6 years until your youngest emancipates... that's a long time.
* College fees/tuition will be paid upon a % of income. IF we decide to pay for the kids college expenses.
In my location, divorce agreements cannot cover anything after the kids emancipate. Emancipation is when they are at least 18 years old and they graduate high school (or their high school class graduates).
The other thing that I recommend is that you listen to your lawyer and specifically... get into the habit of letting your lawyer speak first. You can always overrule your lawyer because you actually get to make the final decision.
Finally, don't take mediation too seriously. The mediator's job is to reach a settlement. Your lawyer's job is to get you the best settlement for you. Opposing counsel's job is to get your ex the best settlement for him.
The worst case is that mediation achieves nothing... and that's not terrible. You can always schedule another mediation session or negotiate without paying for a mediator to guide you.
