Both questions have the same shape: protect the shell, give the filling structure.
Temperature: fillings go in at ROOM temperature. Warm filling melts your beautifully tempered shell from the inside - dull patches, leaks, heartbreak. Too-cold filling sets before it levels, leaving air gaps under the cap. Cook the filling, then let it come down to room temp before piping.
Liqueur fillings: the trick is that the alcohol is built INTO a ganache. The chocolate gives the filling body - thick enough to pipe, firm enough to seal under a cap - while the rum stays vividly present. No soup.
One rule from the chocolate module that matters here: NEVER heat the alcohol. Heat kills the aroma you paid for. Combine the rum with the cooled melted chocolate instead, stir it in off-heat, then fill.
Room temp in, cap, patience while it sets. Weekend batch will behave 🍫
