As PM, one of your main tasks is to make sure the communication and information is flowing to the correct people in the correct way. There's no one-size-fits-all solution (that I'm aware of, at least!) but some important points must be taken into account when dealing with all the documents you have to deal with.
Documentation must be useful. Every line of document you write must have a purpose. Documents are built for an end, there's no sense maintaining a document for the sake of having the document. Remember / review CodeGnome's law, it's also useful.
Understand your audience. As you mentioned, you have a specific report for the boss to track how's things going in a high level view. When dealing with senior management, is important to make sure the documentation is as objective as possible. The time one have available to dedicate to a task (like reviewing a plan) is inversely proportional to his pay rate. Likewise, tracking tasks directly into a Gantt may sound complex, you may think of using a task tracking tool.
Assess what are the common documentation used in other projects. The WBS and Gantt you mentioned are known and should be kept. The word doc you mention you have could be translated into a RAID log, which would be more easily understood by other PMs when discussing about what you have in your project.
Assess what are the documentation with redundant information. And get rid of it. In a project I was working on, there was one Excel to track resources and a MS project to track tasks. Needless to say the first thing I did once I joined the project was to get rid of that Excel.
In the end, keeping documentation up to date and making sure the communication and information is correctly flowing across the project is your main role, so it's expected it to take a considerable part of your time.
I guess it is one of the most common problems - a PM needs to use bunch of tools and methods to steer the project and keep everyone happy except himself. It is true that you need 4 core aspects:
Organizational environment for collaboration
Analytics and metrics
I would suggest taking a look at tools that offer everything in one place. MS Project is a great tool for planning but it is weak on all the other parts. Take a look at Eylean board. It is simple to use and quick to learn but contains variety of features for mature project management and collaboration.