Talk to a solicitor. Any form of agreement ( i.e. signing over anything) should be done as part of a complete package and not piecemeal.
Issues are kids, property, assets, income, outgoings, pensions and going for as clean a break as is possible. While maintenance will always be an issue, in reality, the Courts are increasingly less likely to revisit old settlements - particularly where they have been generous and one party has simply wasted assets away.
Most agreements these days have a clause - "intended to be in full and final settlement".......
mf