There are other options. You may come across a decree of judicial separation. This can be obtained on the proof of the same five facts as divorce, but the decree of judicial separation does not end the marriage – it just states that you can live separate and apart from each other. It is sometimes used for religious reasons or where someone does not want a divorce, yet they want access to the financial relief claims available.
The marriage could also be annulled. Nullity petitions bring an end to the marriage, and the marriage can be treated as void or voidable. Financial relief is also open to the parties to nullity petitions.
If you do not intend to issue proceedings at this stage, then it is possible to incorporate your proposals into a Deed of Separation. As long as there has been full disclosure and you have received legal advice, it is likely that the court will uphold any agreement you record at the time when the divorce goes through if you are not married. Therefore, your proposals can also be incorporated into a Deed of Separation.