Can I ask questions about writing the following types of documentation listed below on Writers SE?
- End User
Yes, questions on all of these types of writing are on-topic here. The questions should be focused on the writing, including processes, rather than the specific technical content. For example, "what makes a good system requirement?" isn't on-topic here, but "how do I make my requirements document understandable to all audiences without sacrificing technical rigor?" and "how do I present such-and-such information while following the IEEE format?" are.
Similarly, some of the document types you listed rely on diagrams; questions about that aspect are on-topic if focused on the communication aspects rather than, for example, how to use Visio to make an inheritance diagram.
See also this answer about API documentation on MSO.