good stuff
1) in AH wouldn't we be able to ditch at lower speed and lower approach speed?
Yes and no. The B-24 will fly slower at the weights used in the test, you can get down to around 85IAS where you'll get some buffet.
What I've heard in hangar talk about ditching is you first and foremost want a controlled contact with the water. Many feel, I agree, that a power on approach and touchdown would be best. If you try to get down to absolute minimum speed you'll have the nose pretty high, upon contact it slams down, digs in and makes for an abrupt stop. And of course if you screw the pooch and drop it in trying to get real slow it would be less than optimum.