The question is in the subject - is there any benefit to removing studs from track spikes between workouts? I was thinking that perhaps if I don't do it there might be some rust issues? I have no problem screwing them on and off between workouts, the question is whether it's necessary.
Never in my 15+ years of experience have I heard of this being done. I've replaced the pins/studs/"spike spikes"/whatever in my spikes a handful of times in my life. A well-worn pair might get them replaced once in their lifetime.
i would check them before each meet or if they felt weird.
You should leave the spikes in the shoes as long as you are able to clean the shoe off with a wet rag (assuming it is super muddy for some reason). But if the shoe is clean, you don't need to take them out until they are dull.
They can't rust because they are stainless steel and the shoe is plastic.
You should make sure they are tight once in a while. People do finish races with a spike or two missing sometimes, though that doesn't really matter since you can run just as well with five spikes instead of six...