>>3 Fairly unlikely that you will be related to Shepard in ME4, also ME4 takes place in the Andromeda galaxy not the milky way galaxy so we will unlikely know what happened in the end of ME3 unless there is going to be some kind of prolog right at the start of ME4.
Eurogamer - copy and past link -
http://www.eurogamer.net/articles/2015-04-20-probing-the-new-mass-effect-4-leak
I suggest watching out for news of ME4