Hi Braf,
first of all, a door serves to bring energy into the house. The actvity of opening and closing the door activates the energies in this sector.
The main element of activation is human qi. A site can have the best feng shui but without people tapping into it, it does not get activated. This is another aspect of the three types of luck. This means the door itself activates all energies whether they are good or bad for you. You should evaluate the quality of the energies in your apartment before placing any cures or activations.
Then there is another thing: my feng shui master is also a qigong master and he demonstrated this year during a seminar to energy-sensitive people how much energy passes through a window pane - almost none! And he really put a lot of effort in it. This experiment showed that glass is almost as impenetrable as a wall.
Therefore, I would not worry about glass in your front door. Simply arrange the rest of your apartment according to your good directions.
All the best,
Astrid