The coffee house
The coffee house is the portal through which Leo discovers the new world he hoped he could find. He is around people whom he admires, and although back home, everyone pressures him to fit in, the coffee house is where he finds other outsiders and outcasts who come to the shop for community. In other words, coffee is a sign for community, because they meet up at the shop. This is a pretty common motif, since that's literally how people use coffee shops, for the most part.
The mother's home
The mother's home is also symbolic, because it shows that Leo is chronically procrastinating. He feels unsure about what to do, so instead of blindly trying to fix a problem he doesn't understand, he just stays, doing what is normal. The mother represents his readiness to be a parent. He just needs to get out of the house, away from everyone's expectations. Perhaps this also points to his character's shyness.
Mardou as an archetype
Mardou's name is a subtle reminder of Marduk, perhaps, pointing to her role as an incisive character. She actually makes an attempt to be correct in her judgments about things. This is why Leo is so fascinated by her—it would be the first time someone actually gave his ideas any credence. It turns out, he is waiting for someone sensitive so he can be appreciated. She represents his own journey toward maturity, because he pushes through his maturation in order to win her.
Writer's block
Roxanne notices that there is a dangerous thing happening. As Leo begins to fall for Mardou, he stops writing. She feels that the writer's block is symbolic of his wrong priorities, but his feelings for Mardou are obviously more pressing. Therefore, the writer's block signifies that sometimes, Leo is in the "living" mode, where he is engrossed in his own narrative life, and sometimes he gets bored and starts writing. It is a symbol of his artistic cycle.
The new family
Ultimately, the artistic cycle is heading toward this completely unnecessary conclusion. Not only does he overwhelm his self into approaching Mardou with his intentions, it also works. Before he can realize what's happening, he is suddenly planted in a new narrative, one where he is the parent instead of the child. He has successfully passed through this journey into his new role.
