They dropped the glowy spines from BSG for exactly that reason.
One MAYBE I could give goauld glowy eyes and dual voice thing come from Naquadah in the blood. They get into that a lot more later, but it's seriously just visual shorthand for us viewers, so we know who is running the show.
Also seems to be mood based, even when goauld should be keeping cover, if they get pissed, they light up.
Not sure what episode you're up to, but I'm going to guess "In the line of duty".
The Goauld seem to be similar to a gallbladder, they excrete trace amounts of Naquadah into the hosts bloodstream, which allows for rapid healing but also may explain why forcibly extracting a Goauld is so difficult.
This also somewhat acts as a werewolf detector. From this point on, if Carter is in a room with a snakehead, she can feel it. The naquadah in the blood ALSO allows someone to operate Goauld devices, such as the hand tool, and a different, healing hand tool. I don't remember what they are called. They mostly use the hurty one.
Ship functions seem to be less locked down than those two, since Jack regularly takes the stick behind Al'kesh, which I like to think of like moving trucks, even though their primary function is bomber/troop transport.
I don't know if it is the Naquadah that makes the Jaffa dependent on Goauld symbiotes.
And you know TV CPR requires the mouth to mouth action, so they can make a nasty joke about it!