It shouldn't have any lone pairs since it is a tetrahedral structure. Ge has 4 valence electrons. Each H has 1 valence electron. Therefore, each H valence electron will pair with each valence electron on Ge.
If it is heated while it is being compressed or held inside a container as such, the pressure build up while in the container and the pressure can become so much that the container will burst.
The amount of the solute is constant during dilution. So the mole number of HCl is 2*1.5=3 mole. The volume of HCl stock is 3/12=0.25 L. So using 0.25 L stock solution and dilute to 2.0 L.
The metric system is based on powers of 10 so it is much easier to convert units, often just by moving the decimal point.