Don't make up questions just because you think someone might ask them. This never produces useful questions and answers.
If you have experience of people repeatedly asking a question in other venues (e.g. you're a teacher and your students ask this every year), then by all means do post that question here. But don't try to ask preemptively. The time to come up with reference questions is throughout the lifetime of the site, not during the first few months.
Be specific. Don't ask “write-the-book” type questions like “What makes quantum computing better than classical computing?”. Such questions are best answered by reading the book, not by attempting to rewrite it on this site. This piece of advice from the Area 51 FAQ is also applicable here:
Ask real, expert questions
We want you to capture the moment that plumbers feel when they look at Plumber Overflow and say, "Whoa! That's my kinda site!" On a site about plumbing, there are 200 easy plumbing questions, and they've all been asked 100 times on other sites. Don't suggest questions like "How do I unclog a drain?" Instead ask, "If you run 2.5 GPM through 50 feet of 1/2" galv pipe, how many psi will be lost to friction loss?" Remember, pro sites WILL attract the enthusiasts, but not the other way around!
Reference questions that serve as duplicate targets are useful, but they generally come after you have experience of what questions people do ask. More precisely, reference questions really tend to be about repeated answers: what answers do you (collectively) tend to write over and over again? When that happens, it's a sign that the answer should be on a reference question, which serves two purposes:
- Exact duplicates of the reference question can be closed as duplicates.
- Other questions that involve the same concept can be answered, but rather than explaining the concept all over again, you give a brief answer that's specific to the question and link to the reference question for the generic, in-depth explanation.
To respond to an idea raised in the comments: a reference question should not be community wiki (this was a bad idea that was abandonned, see the Future of Community Wiki). The answer should be CW if it's collaborative, and should not be CW if it's mostly written by one person. Anyone can edit a post whether it's CW or not, anyway.
Once a reference question exists, the best place to index it is in the relevant tag wiki. I've seen lists of reference questions on meta sites and they're rarely useful: the list is either too big to find what you're looking for, or grossly incomplete.