Congratulations Denise, it really looks good. The wider the blade, the harder it is to master the technique.
I coat an 11x14 sheet with 12 ml of emulsion to cover an area of about 8.25" x 14" The 4" at each end are 'startup' and 'shutdown' artifacts due to the way the paper swells and the dropoff of the blade at the end of the traverse. I take the 8x10 out of the center. You saw some of those at the workshop.
For gapping the blade, cut two strips of 35mm film and put one under each end and then regap. You will have about 0.005" at each edge and with a tolerance of about 0.001" the center should be no more than 0.006".
If you put down too much at too low a viscosity, it does run as you state, but if everything is just right, it will not run significantly.
I found, to my sorrow, that if you don't clean all of the adhesive tape from the coating block when you move a sheet, it can build up and cause a bump to form which increases coatings defects at the leading edge.
Also, some papers are more repellant than others and can cause runs and do buckle as you describe. When I have that take place and cannot solve it by other means, I move the sheet right away to a temporary resting place and tape down the edges. This helps.
Make sure that the paper you use is not less than 100# paper and it should be hard press. Cold press are good, but the texture on them often shows up in the final print.