A child support order only runs for 12 mos, so I wouldn't make deals based on enhanced child support. The only child support you can rely on is CMS (and even that relies on the father not being a complete wazzock).
Judges dont like hearing about domestic abuse, it's wrong and infuriating, but that's what it is, and that's what you're working with. Stick to the financial facts without emotion. Emphasise best interests of the child.
Courts do prefer clean break, but may make a reasonable settlement to you in order to make this happen.
Cohabitation before marriage is added on to the marriage to sum a "length of marriage", but 3 years is still short. You won't get the house, you won't get half, you probably won't get much of a settlement at all, you may get something - after years of statements and hearings and horrid unpleasantness. He almost certainly will come after your inheritance as matters very slowly creak on.
How much does he earn? What equity does he have in his house i.e. after mortgage? If not much different to your £300k, I'd be in a hurry to protect your £300k with a speedy clean break and a consent order otherwise he may lawyer up and pursue you - especially if he's abusive. Be careful, often the abusive ones also pursue custody to avoid CMS and to affect settlement.
Be wise, OP. If your overall position is similar, settle. Many years of your life (and the risk of loss) is not worth it for little difference.