Suggestion 1 seems pretty cool, but it has practical downsides. You also can't watch the jury as an attorney; sometimes those reactions are helpful in fact-giving.

The jury can get readback or playback in criminal trials with redactions for disallowed questions and testimony. So that's already in place - jurors frequently ask for readback.

Suggestion 2 is allowed in California, a relatively new development, and it's done exactly like this. Trial judges can allow or disallow such questioning. In short trials (1-3 days), I'm not sure if there's a substantial benefit, but I tend to like them. In long trials, I think they are great and work great.