Fragments and questions

Fiction writing is far different than formal writing. Not all the same rules apply. People normally speak in fragments, so following the rules would likely make unrealistic dialogue. So fragments are okay, though there is a difference between intentional fragments and accidental ones.

Ignore the beta in about 80% of the fragment cases, and go with your gut. People generally do not speak and think in full College-English grandeur. Sentence fragments can add urgency and personality to a mms. Just don't overdo it.

Rhetorical questions are more likely to annoy seasoned readers. Such questions often reveal an impending attack of Mary Sue. Use them where they offer the most impact.

I got criticized for having my first-person narrator ask too many questions, as well. I was trying to have the scene feel more casual---you're seeing what she's thinking, so when she wonders something, she asks a question. But I was told to limit these because they get annoying very quickly. I think the questions make the narrative more casual, but in my case, I don't want the novel to read like a diary or chat with the MC, so it's good to retain a slight level of formality. Therefore I tried to limit the questions.

As far as sentence fragments go, I use them rarely---only when it fits the narrative. I do use them in dialogue, because that's how people talk. Instead of saying, "That will be fine," my MC says, "Fine." It's realistic. But as for fragmented sentences in the main text, I generally avoid those, unless it really adds to the flow of the scene. If I'm trying to ramp up the tension for an action scene, I might use more fragments. Long sentences would feel out of place, under the circumstances.

Yeah, ignore the beta's advice in this case. There are no cast-iron, bullet-proof, unbreakable "no"s when it comes to writing. You can do anything, as long as you do it well.

Having a beta reader who is inflexible about what you're "allowed" to do could become a problem. S/he won't accept anything except an approximation of what s/he would have done, and that cramps your growth as a writer.

You can always learn from emulating other people's techniques, but you should not be constrained by them. In the end, your writing voice will turn out to be unique.