Both are tricky, but adding more rows to the grid view is simpler. It involves adding the additional rows described in
scrolling the calendar. But this has consequences for the other calendar screens, so try this on a backup before doing it to your live file.
Adding columns to the grid view isn't about just changing a setting unfortunately. You have to extend the tabs, repeating fields, layout objects, script parameters and triggers we have on the layout. Our repeating fields are all defined out to 20 repetitions--14 of which are showing on the grid view-- so if you're careful you can add the additional layout objects, script parameters, etc. out to 20 columns. After that you'd need to start changing other parts of the code and scripts.
I should point out that any of this will slow the calendar down as it has more data to display on screen, so I'd suggest you to be very certain you can't work with what's already there: filtering to show just the relevant resources and clicking "next resources" to "scroll" to the next screen's worth of resources.
Hope that helps,
John