EF is real time. Seat maps are never an indication of actual passengers. There can, and often are, people ticketed without seat assignments. If the fare buckets show Y7, then there are at LEAST 7 coach seats to sell (possibly more, but they won't display higher than 7). If it shows F5, then there are only 5 F seats left, even if there are 10 unassigned. It just means 5 passengers haven't picked seats yet.
Not sure about this. Seems like EF can't be real-time.
I had both my AA reservation seat map and EF's seat map open at the same time. AA showed 7 seats available in coach and EF showed 13.