This is the link to the listing of the Western Heights, which although a Scheduled Ancient Monument does not yet have Listed Building status but is currently going through the process.
http://list.english-heritage.org.uk/resultsingle.aspx?uid=1020298
When the Friends of Dover Castle was first formed about 30 years ago we organised a trip around the Drop Redoubt, and were told by English Heritage that they would be making it safe to open up as a visitor attraction complimentary to the castle in a couple of years. They also have another scheduled ancient monument in the Dover district which they won't even put up signs to in case people know it's there
This is a difficult one as if left as it is the site will still deteriorate, but any development needs to be sympathetic and needs the likes of Paul and Phil to keep an eagle eye not only on what is planned and but what actually happens, which can be two different things as happened with the old post office building.
One final point, Alexander is recommending we consult experts, can he enlighten us on which ones he has consulted to enable him to form his opinions?