Most fpsc users will not understand any of your post as they are mostly hobbiests and the FPSC people at GC never answer tech questions.
Ill say no, dx9 will never have this as it will lose sales of dx10 version if dx9 version has the features of dx10 fpsc.
So id say this is from a sales perspective, as yes, dx9 does support the features you have mentioned.
They do bring out patches quite consistantly, perhaps we will see the features of fpsc dx 10 in dx9 once dx10 is out and they have the sales that they want, so hopefully we get some of the things one sees in the dx10 version.