Which metal halide is insoluble in water?

Assertion: $UF_6$ is more covalent than $UF_4$.
Reason: Fluorine is smaller in size.

Which of the following statements about $LiCl$ and $NaCl$ is wrong?

Covalency is favoured in which of the following cases?

How would you explain the following observations?
$(i)$ $BeO$ is almost insoluble but $BeSO_4$ is soluble in water.
$(ii)$ $BaO$ is soluble but $BaSO_4$ is insoluble in water.
$(iii)$ $LiI$ is more soluble than $KI$ in ethanol.

$STATEMENT-1$: Boron always forms covalent bonds.
Because
$STATEMENT-2$: The small size of $B^{3+}$ favors the formation of covalent bonds.