Pick a sentence..

1. in the highest heavens.
2. I would say, "I'd believe anything you said," or "I'll believe anything you say." I think the "would" is grammatically correct with the "I'll" but it's superfluous.
3. for Texas.
4. The phrase is "barking". It refers to dogs who chase cats; the cat runs up a tree, and the dog guesses which tree the cat is hiding it, and sits at the bottom of it and barks.
5. on Friday, means that the boss comes to work Friday. by Friday, means that the boss comes to work before Friday.
6. That sentence sounds fine to me. As for the question - I'm not terribly strong with the English modal system myself, but there is a difference between something like "you have done..." and "to have done..." but not as much between something like "if you would have done...." and "if you were to have done....". I don't know how helpful that is.
7. I would say "I don't know where she could have gone.

Thanks for that rufio.

Re: Pick a sentence..
1) In the highest heavens
2) I'd believe anything that you would say. (altho i'm more likely to say the other, i think that's correct)
3) I must leave for Texas tonight.
4) I think you are barking up the wrong tree.
5) My boss comes into work on Friday.
6) you could have let me know you were going out tonight.
7 ) I don't know where she can have gone.

I don't know where she could go.
Either will do.... they mean different things

Number 2 is redundant