I can only comment about the coffee table. If you can use a round center ottoman, that may be your answer for a kid friendly coffee table. Put a huge tray on top for holding items.

First, the TV needs to move to the side of the patio door that opens, keeping the traffic all to the right of the family room.

As your children are small, I suggest use the "empty space" behind the sofa for a child's size table and chairs ,a book case and/or toy storage and a good fluffy rug for playing.

Is it 18 feet from patio door to island or TV wall to owner's suite?

How big is your TV? why is the sofa so close?

A picture of the room and furniture would be helpful . The love seat should face the slider rather than block it.

Put a sofa table behind your 3 seat couch. It could have ottomans tucked under for overflow seating. The kids could sit there to colour or build, and you'll have a place to set your drink between wrestling matches :)

That way you'll fill up the space behind the sofa with practical seating while still keeping a nice open path to the patio.

Where is the dining table? I don't see any in the plan.

IMO wihout an actual picture of the space and a proper floor plan I have no idea.