Cracks around door frame repairs

I searched but to no avail. I have a fair few cracks like in the photo around door frames and windows, what is the best way to repair these? Should I use a stanley knife and cut them to a V groove then fill? and should I be taping them? paper or mesh?
The front of the house (brick veneer) has dropped a little over time, the building inspector said that it probably hasn't moved for a while so underpinning can wait (quote was around $10,000).
And yes the strip of cornice is wonky and the ceiling was about to drop and also no undercoat anywhere, all fixed now, the joys of owning your own home. Still better than paying off someone elses house.
One more thing, are the wall vents necessary or can I plaster over them?

Thanks
Nathan

Attached Thumbnails http://www.renovateforum.com/attachm...rs-kitchen.jpg



Read the full thread at RenovateForum.com...