MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
indeed the lines are too far apart. Print some 5 square patterns releasing the 4 knobs the same amount (measuring by its dents) until the center one has fused lines when you remove it from the surface. You could also update your firmware (excellent work by this user: https://www.thingiverse.com/thing:3249319) to get software mesh leveling, as many beds seam to be concave.
Try strengthening the pressure on you extruder spring a bit (could be an easy fix). Exchange stepper drivers (one Z for the extruder) to see if the problem is there.