I have used three main colors for your aparment's color design: white, black and brown.
The priority was hiding a pillars like you mentioned, and my solution for them was to decorate it, so they have a role of shelves . Along with these storages I have added others in the corner of your floor plan (can be seen on renders, and 2D drawings too).
Fireplace is added, as you requested, in the living room. In the dinning area, table for 8 people is created, and there is also space for adding 2 more chairs (extending the table).
