1. A further thought on the endowment. If it has not been assigned to Abbey it is possible your ex cashed it in or surrendered it & that the life company did not inform Abbey. The life company will tell you.
2. Wills. So far as I can find out, no-one except the executor is entitled to see the will before probate, & if probate is not obtained this remains the position permanently - i.e. the will stays private & no-one else is entitled to see it.
3. If probate is not obtained the estate cannot be wound up because the house cannot be sold. The exception to this is if the house is repossessed as Abbey can then sell it. However, as someone pointed out on an earlier post, would Abbey be willing to pay any equity to the executor without probate? Only they can say, & it probably depends on the amount of equity. You could ask them & see what they say.
4. As I've said before, she doesn't need to pay a large amount to get probate if the estate is simple. I believe she could get help from the Probate Office (or CAB) on completing the forms herself, or there are firms advertising on the internet she could ask to quote (although I would be hesitant about using one without knowing more about them).
5. It is possible to take action against an executor for failure to apply for probate, but not until 6 months after the death. Also you would need a solicitor to take Court action & if, as you say, your normal income is reasonable you would not get legal aid.