There are several precedents on SE of sites with near-identical or at least strongly overlapping topics but different audiences:
- Mathematics: Math Overflow for researchers (starting roughly at PhD student), Mathematics for everyone.
- Theoretical computer science: Theoretical Computer Science for researchers, Computer Science for everyone (also covering applied CS).
- Engish anguage: English Language & Usage for native and fluent spearkers, English Language Learners for learners.
- Unix systems: Unix & Linux for people who are typically comfortable with a command line and who typically aren’t tied to a specific variant or distribution, and several sites specifically about one variant and catering primarily (but not exclusively) to people who don’t use the command line: Ask Ubuntu, Elementary OS, Ask Different (macOS).
What makes these sites work is that they’re different communities, with different standards. I don’t think every topic can accommodate this duality. It works for math and CS because there’s a research community (where everyone is a researcher) and there’s a teaching community (where the askers are mostly students and the answerers are mostly teachers). It works for the unix sites because there are different interests, but there there’s more overlap. It works, more or less, for ELL/ELU because ELL has a large pool of potential answerers (native speakers).
I don’t think it would work for programming. There’s no clear distinction between professionals and non-professionals. Non-professionals who are writing a spreadsheet macro or an automation script or a little JavaScript for their website have the same kinds of questions as professionals doing the same thing and need the same kind of answers. Students writing a project have the same kinds of questions as professionals doing the same thing and need the same kinds of answers.
Separating homework questions from the rest is not the same thing as separating amateurs from professionals. Separating homework questions has been tried, and failed on Stack Overflow. It failed because the only difference between a homework question and a non-homework question is the context in which the question arose: it doesn’t make a difference to the content or quality of the question. “Why isn’t my code working?” can be homework or not. Tagging certain questions as [homework] and others not was purely arbitrary, and often led to edit wars. The presence of the [homework] tag was moderately correlated with poor quality, but that was in part because people added it to low-quality questions and removed it from high-quality questions — but quality is a value judgement, not an objective yes/no judgement, so a tag did not work to convey it.
No. Difficulty level is a red herring. Some layman questions may look trivial, but take an expert to get a really good answer. Some professional questions may be subtle, but useless because they’re already covered in the manual. And a homework question could have any difficulty level.
In Rating and moderating questions and askers I discussed having two ratings on questions: usefulness and skillfulness (not necessarily the best names for the concept, please read my post). Adding a difficulty level would not help people find the questions that interest them.