I see. I've just discovered this thread and instantly recognized thrips symptoms in the very first pic you posted in 2008:
Too bad we don't have a decent pest and disease forum section specific to paph (i.e not the rehashed all-purpose S.Bottom pics) with sumed-up symptoms, attempted cures...
Honestly, if I were you I'd send everything to the dustbin. Start over and try not make the same mistake(s) twice:
* overpotted
* underwatered
* mix is too coarse for indoor growing
* I guess would have low humidity also
As an indoor grower, my advice to you would be to grow in a more...
I bought this as a single-growth plant two years ago.
When it first flowered I wondered whether it was a very good delenatii alba. Given that most delenatii alba I have seen are crap, I believe this is the real deal.
The new growth took roughly a year to mature.
That was a few days ago. Three flowers, all different. One has a large, upward dorsal.
I'll try Jakub Szlachetko (x fairrieanum). I believe I saw a cultivar from the originator (posted the pic here a while ago) and it was fine.