Hi, I want to upgrade from IOS 5.1 but worried about what will happen to my current apps . I know they are synced but will everything still be the same after the update ? My chat history , settings for apps , etc . Also, I don't have any space, setup says it needs 3.2 gb of space and I don't have nearly enough . If I delete stuff on my iphone, will it come back once I sync it to my computer ?