Short answers, pulled from the story.
Field Marshal Sir Henry Maitland Wilson replaced Field Marshal Sir John Dill as head of the British Mission in Washington, D.C. after Dill died on the 5th of November.
Heavy artillery bombardment of the Senio defenses began on the 6th of April as part of the build-up to the main assault. The main assault started early in the afternoon on the 9th of April when 825 heavy bombers dropped fragmentation bombs on the support zone behind the Senio.
The 8th Indian Infantry Division, 2nd New Zealand Division, and 3rd Carpathian Division attacked at dusk during the fight there were two Victoria Crosses won by the 8th Indian Infantry Division. They reached the Santerno beyond by dawn on the 11th of April.
Clark set out his battle plan on the 18th of March with the objective to destroy the maximum number of enemy forces south of the Po. The plan required forcing crossings of the Po and capturing Verona.
On the 27th of April, the 1st Armored Division entered Milan which had been liberated by partisans on the 25th of April. The Brazilian Division bottled up remaining German units taking 13,500 prisoners on the 28th of April at Collecchio-Fornovo.