some quick Question about switch and data transfer.

Switch: Is there some way to control which move the switched in character will use? so far it seems for me, that it prefers the first one but sometimes I had the second one too so i am not sure.

Data Transfer: I am thinking about getting a new phone and was wondering about the following. The Games says you lose all your Memory Diamonds if you change to another OS. Does only mean for something like switching from Android to IOS or does changing between different Android Versions count too? (Thinking about switching from s4 to One+3T). And are unrevoked Memory Diamonds safe in the Gift Box when I transfer Data? I have nearly all Memory Diamonds stored Gift Box at the Moment because i am not sure.

Does every 4Star come with a Side Story?