seem to recall seeing a few bits relating to the flue and chimney, can't remember where though, I beleive English Heritage did something a few years back.
The small reservoirs, probably for the periodic flushing of the flue.
not been up there for a while, usually all dry but there's been a lot of the wet stuff here the last few weeks, there's a few collapsed shafts from lintzgarth level that run that way so maybe a few of those flooded at present as well