Hints for Improvement

Any ideas on how to improve this? I am going to adjust the front idler position to fix the high/low front corners but would like advice on: 1. The blue spot on the left - this causes the most pain with getting a decent first layer across large prints 2. The bow in Y direction - I have soaked for a while and then loosened rail screws but not much changed. This is after a heat soak at 110 and z-tilt. I have an extrusion-less x-axis.