Heya,
Looks great and what you said about body structure makes sense.
They do have tails -- they don't show up frequently in screenshots (Kilrathi in the games are usually wearing pressurized armor or capes), but they're there. The most famous instance I can think of is the winning endgame of The Secret Missions, when Gilkarg is executed. You see his silhouette with a tail swaying back and forth before he's disintegrated. Another notable example is from Freedom Flight, where Hunter notices that the captured Dralthi have holes in the seats for their pilots tails to stick through. (I was a Kilrathi in the Dragon*Con parade last year... I forgot to take my tail off afterwards, so I ended up being an ordinary person with a tiger tail for a few hours.)
Re: their social status. Females aren't part of the government or the military, but they have a large amount of control over these things. The Kilrathi religion, the Cult of Sivar, is run entirely by priestesses... and Kilrathi beliefs are so well entrenched that the priestesses can exert a large amount of control over the military and the government. Prince Thrakhath had to tread carefully when it came to matters that the priestesses had some interest in -- conflicts between the formal government and the more progressive cult priestesses were at the base of why planets like Ghorah Khar split off from the empire.
I wouldn't worry too much about facial structure -- it's supposedly very varied, with 'rougher' lines indicating "less noble" blood.