(1) Yes, I believe that you are 100% correct: dreams.
(a) Here in the States, sometimes a young man will tell a young lady:
I think you like me. And she might answer: In your dreams!!! ( = you
can only dream that I like you, for I do not like you)
(b) Yes, I believe the than is absolutely necessary, but I think it would
be helpful to delete the more. As you know, clearer = more clear. It
would not be helpful to say more two times.
P. S. You could use a dream this way: I had a dream last night that I
was in Egypt. But if it occurs regularly, it is better to say: I have
been to many places in this world, but only in my dreams.