Here are some of the things that we've implemented that have helped us manage visibility and work for our users, especially the Planners (apologies in advance for a longish post):
1. Set up your Portfolio/Program structure and Inherited Permissions appropriately (this may not apply if your Planners can/should have visibility into all projects). We have our Portfolios set as the major departments (Office of the President, Strategic Enrollment Management, etc.) then the Programs are the units under the Portfolio (Analytics and Decision Support, Communications, Marketing, and Enterprise Operations fall under the Office of the President Portfolio) - this not only helps manage work and visibility but also mirrors the structure of our organization. Everyone who works in one of these groups has View Access to the Portfolio and Program but Inherited Permissions are removed at the Program level. This way people working on projects under each Program cannot see what one another are doing, but can still work together. We did this because several of the groups work with sensitive information.
2. Establish "Must Haves" for opening projects. We have determined with our Planners that when they open a project they must include: a Project name, Description, Portfolio/Program, and Company (which we use as Customer or who the project is serving). These are communicated to the Planners from the onset and we run reports to see which Planners have not completed these fields and send them reminder emails. This helps with consistency and visibility at higher levels (if one Planner is out, another can see what the project is and continue the work if need be. If an exec/higher level staff were to look, they would have an idea of what is being worked on.)
3. Superuser Structure. Just like you, we only have 2 Admins with limited time, so we implemented as Superuser Structure. We adjusted the Planner license so they are not able to do some things (ex. delete projects and add users) and shifted those responsibilities to the Superuser (one Superuser per Unit). The Superuser is also responsible for training new users in their Unit. This has helped take some of the pressure off of us as Admins. We are in contact with Superusers to make sure things are going well or finding out if there is anything that the need help with.
4. We came up with an FAQ (see attached) that apply to all our Planners and Workers. This has also helped take some of the burden off of us Admins as well as the Superusers. The FAQ we've created is a working document and we add and change things as needed. We added this to the Documents tab in the Global Nav bar and it populates into everyone's Smart Folder there.
5. We created a Workfront Help queue within Workfront itself which is open to all Planners and Workers. All request filter to the Admins and include adding/deactivating users, password resets, project deletion/restoration, and general help. This helps stream line how we are getting request so that we don't get an avalanche of emails.
Hopefully something in here was helpful!