I Just Don't Understand

I just don't understand

I have so many questions. - Why is Molly so happy in the final scene of TFP ?? - How could John magically be free from the chaines ? - Did “Mary” worked with Moriarty ? - Why did John nothing when Sherlock wanted to shoot himself ? - Why was Eurus flirting with John ? - Why did Sherlock didn’t sit down when they watched the message from “Mary”? - Is this John’s dream ? - Did he get shoot? -Is there going to be a 4th episode ? - Why is the whole crew saying nothing ? - How could get everything good just because of a hug ? - What happend with nurbury ? - Why did Sherlock ignored Vatican Cameos? - What does “Mary"mean with I know what you two could become ( Johnlock?)

TFP wasn’t bad( my opinion!) but I need answers!