I'm surprised he's not banned yet. He's probably getting warnings at least.
MrPointyhats, if you are not a troll I'd like to say a few things. You were the first one to start being sarcastic and possibly come off as rude, so technically you started this. I suggest trying to make your posts with as little snark to them as possible even if you're just joking to avoid people getting offended.
A smiley face here or there helps too.
Second, on the subject of probing it's something that should only be done by someone with experience. A reptile vet should know how and not charge TOO much, but if you can find a breeder in your area that would be better. (cheaper)
I would stick with mice as a staple and stay away from rats for now, or only use them as a treat. They are high in fat and over time can make your snake fat, which is unhealthy.
And as far as cohabitation goes, there are some very real risks there and in general it ends very badly for one or more of the snakes. That is why no one recommends it, it usually (but not always) goes downhill. Now if the risk was something small, then no one would care. But the risk here is, at worst,
death.
So, here is the only way to properly cohabitate corn snakes. Start with an enclosure 40' wide, 40' deep, and 6' tall. Add about 20+ hides, 5+ basking areas or heat pads, 5+ water dishes, and as much decor as you want. Then, quarantine your snakes for at least 6 months before introducing them. After that release them and hope they don't eat each other.
My point is that in order to avoid the risks of stress you have to house them in something so large that it's as if they aren't even together. And even then, you still can never take away the risk of cannibalism, spreading of disease, and unwanted breedings.