Condolences.
The attorney is right - work directly with your STBX (soon to be ex) as much as possible. What is left over that you can't work out yourselves, try to work out with a mediator. What is left over after that, try to work out with lawyers. What is left over after that, is court. Each step in that chain takes longer, is less certain, is more expensive, acrimonious, and stressful. It may be strategically smart to flex/accommodate/give in to your STBX rather than pay lawyers $500 an hour to argue over smaller things.
There are three financial parts: asset division, alimony, and child support. In my state, they all operate independently of each other. The also operate independently of "fault" - the court doesn't care. They also put the welfare of any kids much higher than either parent's needs/wants/hopes/desires.
It may vary by state, but asset division in my state is assumed to be 50/50 regardless of who earned what and who spent what. What we did, and I think is most common and easiest, is for you to take all of "your" assets, her to take all of "her" assets, and then make one equalization transfer to get to 50/50. Equalization transfers incident to divorce can be made tax-free via QDROs, and depending on which asset you choose to QDRO could result in the other spouse ending up with a new retirement account at the "donating" spouse's custodian/employer. So in your case, you get your Roth, your TSP, your checking, your life insurance, your car. She gets her Roth, her checking, her car. Then you probably split the taxable account in whatever way leaves you at 50/50 - it looks large enough to balance things out and you'd only have to deal with splitting one account and doing one transfer.
Asset division in our case was based on the current value of the assets at the time of the divorce. Tax implications, cash flow implications, and risk implications were completely ignored. Whether they come into play in your case probably depends on how financially sophisticated she and her attorney are. My ex and her attorney never mentioned anything along those lines. I thought about them and suggested asset splits which worked better for me; she accepted them.
Alimony in my state is rare and usually done lump sum. My ex got some alimony because she was a SAHM and the mediator thought she could successfully argue for some in court. If you're both college educated with jobs, and since your assets are large, you might be able to argue for no alimony.
Regarding child support, every state is required to have child support guidelines. In my state, and I believe in most or all states, the divorce court assumes that the child support guidelines are correct and the formulas therein produce the "correct" amount of child support. In my state, the formula inputs are the incomes of the parents, the number of children, and the custody percentages of each of the children. The higher the income and the lower custody percentage, the higher the child support payment. In my state, child support basically ends when the kids graduate from high school.
It mentioned that a portion of the TSP could be split off into a spouse's IRA and I'd owe taxes on that transaction which is why I'm trying to run that down. I'll keep digging and see if I can find anyone who has gone through that.
That doesn't sound right to me. I would check with a tax person on that. In my case, I did a QDRO transfer from my traditional IRA to my ex's traditional IRA and it was completely tax free on all sides. The QDRO was written into the divorce and I may have referenced it when submitting the transfer request to Vanguard. I don't see why a TSP would be treated any differently, although it's possible it might.
ETA: Divorce laws and practices are state specific. Except for the first paragraph above which I think is generally true anywhere, you should really only take input from people who know your state's laws - either people who have been divorced in your state or divorce attorneys in your state. I live in and was divorced in Idaho, and some or all of the rest of what I wrote above may be different than your state.
HTH.
