It’s a Tannaic dispute whether non-Jews are prohibited in witchcraft. According to Sanhedrin 56a-b:
The Tanna Kamma holds only the basic seven are obligatory upon them.
R’ Chananya Ben Gamla adds blood from a living animal.
R’ Chidka adds castration.
R’ Shimon adds witchcraft, and R’ Yosi adds that all forms of witchcraft mentioned in that passage are ...
The Amidah is said from the perspective of the Jewish people/congregation, as it begins "velokai avoseinu", and as is indicated in other brachos as well ("hashiveinu avinu lsorasecha","tekah bshofar lcheiruseinu","hashivah shofteinu").
Thus in the brocha of refaeinu the 'us' in 'Heal us...', is referring to the Jewish people just as it is throughout the ...