It's preferable to avoid plasterboarding an entire room (time/cost), moving a large amount of sockets in the process if there is a viable alternative.Seeing as you are going to get boards in for (1) why not get some more for (2)
As per my earlier comment, it wasn't like the walls were peeling off on their own accord. The chase has unveiled the poor skim but it's not poor all over as other than the bits I've removed the rest isn't budging without a chisel. I 100% get there is a perfect solution which in this instance is "there are glaring signs the skim is poor, ideally remove all and start again". I'm just hoping/wishing that in a real life practice example, there is another option which although not guaranteed is highly likely to suffice.
I'm stressing the hoping part as could really do without the cost of the ideal solution