We know of the first 11 Amos in the Azoroh, where non-Kohanim could walk (Ezras Yisroel).
Could a Yisroel go further in at all? If not, presumably Shechitah of Korbonos requiring "Tzofon" could not be
done by a non-Kohen, according to 2 out of 3 opinions regarding the area of "Tzofon".
(It is interesting to note the pesukim in Korach restricting non-Kohanim from the Ohel Moed and Mizbeach)
The Mishnah in Kelim 1:8 tells us that a Yisrael may enter further into the Azarah than the 11 Amos if he does so for Semichah, Shechitah, or Tenufah.