How does $LL(n)$ languages compare with $LR(0)$, for $n>0$?
They are incomparable.


Every $LR(0)$ language has the prefix property (no sentence is a prefix of another sentence). But many $LL(k)$ languages don't have this property ($a^*$, for example).
The language $\{a^nb^mc\mid n\ge m\ge 0\}$ is $LR(0)$ but is not $LL(k)$ for any $k$.