Questions with declarative forms have the same meaning as their interrogative counterparts or not?

“So you can do what with it?” (The Postmistress by Sarah Blake, p.118)

And the focus of your research right now, Charles, is what? (Woman’s Hour, Mon, 28 Apr 14, 14'18")

Can above questions, not having subject-auxiliary inversion, be used as the same meaning as their normal syntactic forms: “So what can you do with it?”, “And what is the focus of your research right now, Charles?”

I find no differences between the two forms above, yet I’ve only read in CGEL that those types have some epistemic bias towards a positive or negative answer. Or they are used when what you heard is not clear or surprising (p,881;p.886). The questions above are or can be just simple, unbiased, questions or not?

Answer

I don't think either of the specific questions you give as examples has a bias towards either a positive or negative answer, because neither can be answered with a simple positive or negative—they’re both ‘open-ended’ questions, conditioned by the what at the end of each. They can be spoken with varying emphasis and intonation, which may commit the speaker to a specific attitude. But that commitment is not a function of the syntactic form; the same attitude may be conveyed by emphasis and intonation in ordinary interrogatives

These, however, may indicate an ‘expected’ answer:

You can ask questions like this?
The focus of your research is English interrogatives?

These may express dismay, or excitement, or skepticism or confusion about the addressee's prior assertion of these propositions. And in fact, at least to my mind, what distinguishes questions of this sort from ordinary interrogatives with Subj/Aux inversion is that they are almost always responsive. That is, these questions are not used to initiate a discourse or to introduce a wholly new topic; they have to pick up on something that occurred earlier in the present discourse. Note that each of your examples opens with a conjunction, implying a continuation of something previous. My two examples likewise imply an established topic:

[So you are telling me] you can ask questions like this?
[Do you really think that] you can ask questions like this?

[I didn’t quite catch that …] the focus of your research is English interrogatives?
[You say that] the focus of your research is English interrogatives? [You’re not interested in French interrogatives?]