'I thought', 'I would think', 'I would have thought'

Solution 1:

I’m sure all of these variations are commonly used and understood to mean roughly the same thing. “I would have thought…” essentially means “I believe you should have understood what I meant,” or “that should be obvious.” “I thought that was obvious” is a simple declaration that sounds more like the speaker actually gave the matter some thought.
“I should [not “would”] have known,” means that she realizes, after finding the boys, that she should have expected to find them where she did. “I knew you would be here” is similar, but means that she went straight to wherever she found the boys based on her knowledge of their habits. Both phrases might imply some disapproval of their being there. “I would know” (or “I should know”) is not a possible substitute for your sentence. As a complete clause, it’s more like “you can take my word for it,” or “take it from me,” implying some experience of a situation, often said ruefully or with a little chagrin.
“I don’t/wouldn’t know”: There wouldn’t be much reason to answer “I don’t know”; it’s more direct to just say that you weren’t there. “I wouldn’t know” might be employed where there’s some displeasure, like if B thought he should have been invited to the party but wasn’t. The “would” in “I wouldn’t know” is present tense; “I wouldn’t have known” is not possible here because it puts it in the past tense.