I bought a rather battered Victoria plum tree yesterday for £1.99 and if it
grows it grows. It has broken branches all over but is showing growth on
the remaining bits. The roots are showing growth too.

I have it in soak now in a bucket of water.

I want to give it a good start and would like to know whether to plant it a
hole with compost or just soil with blood fish and bone (or any other
reccommendations)

I have read that using compost is not advised because the roots would like
to stay in this and not grow outwards into less fertile soil. I have also
read that compost is a must!

I have planted healthy bare rooted trees before, but not a "sickly" one so
I would like some advice please.
Oh, and because of broken branches would it be more prone to Silver Leaf?

Thanks
Baz