The Chronicles Of Narnia Prince Caspian question?

I have a several question about the chronicles of narnia prince caspian i was getting kinda confused and i wasn't listening good. Well my first question is how come the lion asgrian or something never come back while the war was going on with the narnias and the tamborians. second question did the tree's move in the chornicles of narnia part 1. also in about the part where lucy shows her dagger and all the men come and then the lion comes and he roars and then that water monster comes out and owns them all was he in the first part and who was he and how did he come. My last question is so susan and that other guy the young king won't be able to go to narnia anymore even if they blow that horn thingy and how come they won't be able again and what if they secretly go in or something.