My E-Cig itself has never been questioned. It's in an eyeglass case which I place in my computer bag while going through Security.
Passthrough's: Place your passthrough in some kind of plastic or cloth sleeve. Zig Zag the wire with the pass through, and push it into the sleeve. It will be neatly wrapped, and will not look suspicious.
TSA will notice a passthrough which is just laying loose in a purse or bag compartment, as a "tube with a wire in one end" They'll definately stop you to check it out. What they will do afterwards? I have no idea, it never happened to me.
Your juice should be no problem. A 30ml bottle of juice (1oz.) is well under the 3oz. limit. It has to go into the famous zip lock baggie. I suggest you double bag it with another zip lock bag. Roll it up, and place it with your other liquids. I double bag mine in case it leaks. I also remove the dropper, cap the bottle, and put the dropper in my shaving kit.
HAve a safe flight.