The weather in Normandy will likely be chilly in April so you won't be basking on the beaches. Personally I'd shift Day 3 to the Loire Valley so as to have 3 days in the Loire instead of Normandy, but if you are more interested in WWII battle locations and other sites in Normandy, then your time allotment is probably fine.
It looks like your route will take you through the western side of the Loire region, which is great because it is less heavily touristed, being out of range for day trippers from Paris. I can recommend Hotel Biencourt in Azay-le-Rideau. The proprietors are very friendly and helpful, and it is a lovely property just down a quiet pedestrian street from the chateau. From Azay-le-Rideau it is less than an hour's drive to the Fortress of Chinon (connections with Joan of Arc, Eleanor of Aquitaine, and the Knights Templar), and in the other direction the chateau of Villandry (famed for its gardens).
Alternatively, you could stay further west (Saumur, Angers, Brissac) and see Fontevraud Abbey and the Cadre Noir performing horses in Saumur.