Expert users vs. Newbie users
Talk to both types of users.
Expert users will know the common pain points for features that are used a lot or impact the bottom line, which helps decide which features to develop in the upcoming development cycle.
Expert users will answer questions that you should be asking. You may not know what to ask if you are new to the system or even the company. An expert user will know this and help you with what you should know.
If you find a user like this, develop a good relationship with them and ask them if you could use them as a resource in the future.
A newbie user can tell you how easy or frustrating it is to use the system. This information helps UX designers. You want features to be discoverable and learnable without much help. Watching a new user use the system can tell you that.
With expert and newbie users, they will tell you solutions. Scribble them down, but they may not be the right solution.
Design is not for everybody. Users don't surely make good designers.
Let the design team come up with a solution. It is better to capture their idea, pain points, and goals and use that to develop a design.
Perhaps the design will be similar to the users' solution, but maybe not. Either way, write down what they say but don't anticipate it being the solution.