Conceptually an ipad does not fit the usage you have stated as that fits how someone would work with a laptop, an iPad is a companion device that gives rapid access to business information but i would never replace a laptop with one.
Ipads have no concept of a file system so you cannot browse file shares in a traditional manner, personally to enable the speedy disemination of data stored in files in my company we use SharePoint with the SharePointPlus app. This gives the capability to browse SharePoint document libraries, view and edit files that reside within them. This is the easiest and most fluid way of working with documents on an iPad in my opinion because of the nature of how an iPad is used.
You can get an app for accessing exchange public folders over outlook web access, there are wireless printing capabiities but this will depend on your hardware and network capabilities.
What the iPad is good at is providing instant on access to email, calendaring and the web, working on an ipad is very different to working on a laptop and if your boss isnt a big fan of changing how he works then it may not be the right tool for the job.
I've implemented 20 iPads in my company used by directors, account managers, senior team leaders and and they all use them in different ways.
I could type for hours about this but im off to the pub so if you have any other questions just ask and ill get back to you later