How's the bird situation on the surrounding cliffs?

Most of the cliffs have a good deal of bird poo on it and dried out crumbly lichen. But climable. Only a few sections have nesting birds on them, small sections with high concentrations of nests. Can't say for all routes as didn't see them all but there seemed to be a lot of nests with eggs and more birds mating on ledges. Suffice to say choosing route when you get there is wise as they are in full mating swing! Lol below fastcastle and to right of Souter were bad, also landside of Souter but not sea side.

What is the actual height and how many pitches thanks

Guidebook says 25 metres but at really low tide the first 5 metres is more a scramble than a climb. A 60 metre rope will get you back down easily, a 50 also will, if you abseil down the hvs seaward side. There was a few bits of tat at the top last year to ab off.