It just seems way too powerful to me, and its powers are all over the place. It can go through anything (except barium) and kill anyone with a simple touch. It's malicious and somehow has information about the Foundation (shows up in a shirt with another skip on it). It cancels out all monitoring devices, changes sex and appearance, hovers and glows. And it can wipe out an entire town? How? I thought it had to make contact with a human?
Also, why did you choose barium? I'm no expect on barium (shocking, I know), but doing some quick research leads me to believe this probably isn't the best choice for a weird metal "just because". Barium is a seriously reactive metal, and simple contact with air can cause it to ignite
(other ignitions include moisture, friction, heat, sparks, flames, shocks, and static electricity, at least according to Wikipedia). Apparently it's stored in an atmosphere made of argon or under mineral oils. I don't think a room made of this stuff would be plausible. You seem to be aware of this per the no water allowed near the cell but didn't mention anything else.
Your punctuation and grammar are good, only caught a few mistakes that can easily be corrected (lead instead of led), but the clinical tone needs to be polished. "Face slowly lit by smile" is unclinical prose, and the conversation with the doctor is pretty clichéd and doesn't read real. ("Every here and there"? This is very awkwardly phrased. Do you mean every now and then?)
TLDR: Humanoids are notoriously difficut to write on the site, and as it is now I don't think it'd survive. It's not enough for a skip to just exist anymore, the article has to actually sell a story for Series 3. I'd definitely start by removing some of this skip's powers and give us a reason to care about it. Where did it come from? Where's it been? What are its motivations other than killing 'cause it gets off on it? It can't interact with solid objects, so does that mean it doesn't need to eat (beware: this is already way overdone)? You don't have to explain away everything, some things should remain a mystery, but you've got to give us more than this to leave us wanting more.