You do contract work my friend. Whatever your contract describes and nothing more. Nothing less either.
Are you employed to audit the business model of the company that signs your paycheques? If not, then don't.
I understand your ethical concerns, I've been in your shoes many times. But what your employer does with your time, skills and their money should not be your concern, as long as you have no stake in the company.
What I did to navigate this kind of situation was to subtly nudge my employer into giving me more complex tasks that were in line with my skills. Avoid making major changes without asking for permission first, as it might be seen as breach of contract.
In this specific situation, without understanding the exact context you are in, what I did is I tried to automate as much of the boring stuff as possible. If your company has stuff like Confluence or some other similar tools, try documenting the most common answers there in an easy to navigate manner and just refer further questions to the pages.
If your coworkers are willing, try to spread this information around, so that if your boss is not around, someone can still answer the questions.
Lack of proper documentation is a common issue in many companies. As a contractor you cannot fix their way of documenting work, but you can raise the fact that this makes the contract a lot harder to fulfil. Make a note of all missing documentation and make sure your manager has it in writing, so you cover your ass in case someone upstairs asks why the contractor is so slow at his job.
Access to company resources is a PITA for most contract works I've done. Either credentials to login, access to onsite resources, code repositories, discussion groups etc. If this is your first contract work, it makes sense you're concerned if they failed to give you credentials to login for a long time. It happens. I've had a colleague that billed a company for 3 months without ever accessing his work laptop because they never provided credentials to login. It took the IT dept of that company that long to generate credentials for him. Without them he could do nothing productive, but he had to be available on phone to get on the team meetings. So he billed them and they paid.
If this is your first contract, I can see why you're so concerned about all this stuff. But know that this kind of things happen. And it's not your fault, or the hiring company's fault. Just fulfil your contract to the best of your abilities and try to help your coworkers if you can. Everything else is out of your control.