Have done this cruise with Bora Bora instead of three days in Tahiti. Unfortunately Bora Bora now allows only small ships to anchor there. We loved the cruise because we enjoy sea days. There are 19 of them, 8 straight at the end. Unless the Crown Princess gets their propulsion issues resolved the itinerary may be modified. For that reason I would select March to give Princess additional time to correct the issues. There are only two stops in Samoa, American Samoa and Samoa. Both of these ports are interesting, but limited tours and activities. Note that if you take the March trip you will go to sleep on Friday March 31 and wake up the next morning on Friday March 31. Two ports in French Polynesia, not 4. You will have 3 days, 2 overnights in Papeete. There are tours and other activities there. Not much on Moorea. Just one small store near the pier and one small general store up the street. Believe there is a hotel that gives day passes. There are also some tours. If you book recommend you become active in the roll call.
Port/Starboard, no difference. You are heading basically north & south.