Can I use my MacBook Pro as the screen for a mac mini
This answer only uses the HD of the Mac Mini, while the processor and memory of the Macbook, which is not the definition of "Screen", but you'll be able to use the contents of the mini as use it as a boot disk.
- Turn both machines off.
- Boot the Mac mini into target disk mode by (a) holding the "t" key as the computer starts up, or (b) setting "Target Disk Mode..." in the "Startup Disk" system preference.
- Connect a Thunderbolt or FireWire cable from Mac mini to MacBook Pro.
- Boot the MacBook Pro, holding down alt/option key.
- Choose the Mac mini hard drive when you get to the screen that shows the available disks. It should be the one with the FireWire icon (if you used that cable).
- Voila, your MacBook Pro has booted from the external Mac mini, using it as its hard drive.
Hope it helps.