Footprint of ours is 65 over a 48, but we pulled the cooktop out, as well as the flanking 9" pullout cabinets. 54 should be fine.

Perfect! It's highly recommended that the hood be at least 6" wider than the cooking surface.

If the range is against the wall, the hood should also be 24" deep.

Ir the range is in an island or peninsula (which I hope it isn't), the hood should be at least 27" deep.

Yes, if you have the room.