Congrats on your new purchase

Insurance - NFU are the best I believe. I have one of mine with Scottish Equestrian and they were excellent at paying up - no quibble. The rest are with Pet Plan. I have had two claims and both times they dragged their heels so much and made it as difficult as possible to get a settlement that my horses, both times, could not receive the treatment they needed

Although their monthly premiums are cheaper (not much good though if they do not pay out).
Regarding softening leather - I understand recently that it is no longer felt that animals fats are the best for leather. It blocks the leather. I will look into a good make and let you know.

Good luck with your new horse.