The kitchen flooring came in. It looks awesome. $4/s.f. 1x3' marmoleum click flooring in eucalyptus color from greenbuildingsupply.com.
The flooring instructions say to leave it in the room it's going into for 3 days minimum. THIS IS NO JOKE. It WILL buckle. Wood click flooring takes even longer to acclimate - usually 10-14 days. You should take this seriously and take seriously the edge gap specs. If the flooring has no room to expand or contract that will also cause it to buckle.
First piece will dictate square. If the back wall is off, then the whole floor will be off.
The 3/8" expansion joint needs to be covered with trim.