Gravity is down to 1.009 without there having been any visible kraeusen. Is that worrisome?
Not if the beer tastes and smells good. Some strains produce more krausen and ferment faster than others.
It's Thames Valley. I perceive a quite strong sulfury smell. Is that typical for this yeast?
Not typical IME, but I wouldn't worry too much. Sulfur dissipates with time, and you can help out the process by venting the keg periodically (assuming you keg this).
First you tell me that I shouldn't worry if the smell is good. Now you tell me that I shouldn't worry about the sulfur smell. When exactly should I start worrying?
The sulfur will dissipate. If it tastes like crap 6 weeks from now, worry.
BTW did you use the SS chiller for this beer out of curiosity? I ask because the wort being in contact with copper (as in a copper chiller) is known to reduce sulfur levels. All this stuff about low O2 brewing seems (by avoiding copper)to introduce the possibilty of sulfur-y beers. Again, the sulfur will dissipate though.