help me with a few things!!

ok being the biggest gael garcia fan, i had to have this and i think he played his small but key role amazingly well!!!

1) why did he have a bomb was he planning to use it?
2)was julia and che having an affair? and did everybody all ready know because he said to the boys grandmother 'he knows', meaning she already knew but she was still with him?, i was so confused. and when the 'rebels' went around the town shooting and causing havoc why was the police officer in the car with them?
3) and why did julia feel the need to save ricky? if he had bombs and guns in the first place?
4) why was julia an air hostess at the end? i thought she had died, was he imagining it?

HELP