That's all great. As long as the OP can convince the court of everything, and his ex rolls over and doesn't fight it.
It would be very easy for ex to say she's now a stay at home parent and does all the domestic stuff while OP works his 'long hours'. Especially after taking legal advice. That will sound more plausible to the court than the OP does everything and ex nothing.
The OP seems to be particularly focussed on keeping the house above all else. Op will have to be careful not to open himself up to accusation of being financially controlling.
If it goes to court the judge would take the welfare of the children into account
And if its decided that the children would be better served staying in the house then I can keep it
The judge would put the welfare of the children first, not just into account. They are unlikely to decide that it's best for the children to stay in the house if the OP can't raise enough of a mortgage alone to buy her out.
If they award the OP's ex a 'future payment' from the house, it'll be based on percentage share, not a flat 40k or whatever. That could end up being worth 80k by the time the youngest child is 18.
I've been working then coming home, making dinner, washing up, doing the kids homework whilst she just goes upstairs and plays with her phone
I do the shopping, meal planning, bulk of the washing and general house tidying
(I do however earn above average and work in sales with long hours)
It's impressive that you're able to fit all that in, in fact it's impressive that there are enough hours in the day for it. I'm not at sure how working long hours is realistically compatible with being a single parent.
I do not expect childcare to be an issue as such, we get in fine in that respect
She will visit most days for dinner and have kids eow
Who's 'we'? Reading between the lines it sounds as though the OP is planning for his ex to provide wrap around child care to support his long working hours? Meet the kids out of school, take them back to the OP's house, give them dinner and then leave when the OP gets home from work? That's not going to make it easy for the ex to get a decent job is it?
Or if the OP means using professional child care while he works his 'long hours', I'm not sure the court will decide this is in the best interests of the children when their mother not working and available to be primary carer. Sounds like the OP has higher earning potential and the court may decide it overall better for the children for him to be the NRP and support the ex whilst she stays in the family home. Also, I suspect it's more a case of the kids saying they want to stay in the family home, regardless of which parent is living there with them.
And I'm saying this as a single father of 3 myself. I just think OP is being rather optimistic with the settlement he's proposing.