Walls are straight and have read the recommendations but they do not state what fixings to use. For example will frame screws like the ones below hold it in place?
http://www.screwfix.com/p/rawlplug-pa6-nylon-frame-fixings-10-x-100mm-pack-of-50/39351[/QUOTE]
Assuming these are screw-in, then I'm sure as a fixing they are fine.
I've used the hammer type ones on some skirting board recently and were generally ok, but where it needed a bit more 'pull', they didn't seem to deliver and I ended up unscrewing it and refixing with a decent screw. There is also the fact that the blocks in the wall are not solid and if going in to a void part, it limits the contact between plug & block. Which may be a factor for you also. Personally, where the usage you are considering, I would prefer it to be a secondary fixing, rather than the primary.
Still on the dry wall addy topic - adhesive can be applied continuously around board edges, window frames etc which allows a solid outer edge. Useful for skirting board fitting for example.
For me, for £5/bag of adhesive it's a no brainer. I would use it anyway. After I've taken the time to skim the full room, paint, fit my carpets - I would not want to have to refix a board later.
You are of course free to make up your own mind. I may only be a DIYer, but you've had a lot of good advice from seasoned pros on this forum so I hope you at least carefully consider it.
Good luck with the project.