Is it possible link one view into multiple sheets? I would like one key plan to appear in all of the plan sheets.
Legends and views can be inserted in multiple sheets. Since you need a keyplan, use a legend view.
Does that mean that this key plan needs to be drawn with detail lines? Which means that the keyplan will not be parametric?
Well, it will not be a live view. Usually, what people do is an annotation family with visibility parameters and hatch patterns, to turn on and off areas, depending on each view. If it is a tower, you need 2, one for the plan, one for the section.
Alfredo was not talking about drawing the keyplan directly in the titleblock family. His suggestion was to create a generic annotation family that can be placed anywhere and used as a keyplan.
Attached is an older tutorial that covers the basic steps for doing this. The tutorial was written for Revit 2009 (pre ribbon interface) so you may have to do some interpetation to find the commands, but everythign should work pretty much the same now.