This was going to be a comment, but got too long, so I'll post it here.
it really depends a lot on how many questions we are talking about, since you want the user to go to any question, that means that all of them have to be present all the time, if you have the titles of all of them, the user, most probably wont read them unless he has to, plus it will be a long page.
If you have, 400 numbers, it may fit on a page, but why would the user click on question 200? or 158? or any number, they don't mean anything. And what would happen if you have 1000 question, that won't fit on a page, not even using just numbers from 1 to 1000.
If you use a method like listing numbers, you could show the summary of the question when the user hovers over the number, but that would also take a lot of time since all the numbers would be visible, consider that you would have to make a ton of AJAX requests to show them.
A slide is not good because you don't have a precise control over it. Plus the more question you have, the less precise it will become.
The only way to give direct access to all the question, would be to show the total number of questions and an input where the user could write the number of the question he want to see. But again, why would the user want to go to a random question?