Meaning of sentences with should/would

These sentences are from "A Practical English Grammar" published by Oxford. (By the way anyone heard or think this is a good grammar book? This is the only English grammar book written in English that I finished reading from cover to cover, and I think this is very good. I wonder if this book quality is ordinary or excellent.)

1. He's an astrologer, looking for work. ~ I shouldn't/wouldn't think that he'd find it easy to get work.

2. He actually got a job as an astrologer. ~ I shouldn't/wouldn't have thought that it was possible to do that.

3. She has emigrated. ~ Has she? You'd/I'd have expected her to stay in this country.

4. It is amazing that she should have said nothing about the murer.

5. I can't think why he should have said that it was my fault.

What do they exactly mean? I am having a hard time to understand them because of "would/should" things.

Thanks a great deal, fellows.