Let's face it: only YOU really know if you can store a firearm safely in your pad- roomates or not.
With regards to alcohol, its stupid to think that guns and drinking can ever mix. If you want to know what happens when they do, even under the best intentions, just look back at the Old West, when men carried their sidearms into the Saloon. Undertakers were very busy back then. With alcohol, tempers flair and judgement is the first thing to go out the window.
If you're going to live in a fairly confined space, where there is alcohol, don't introduce a firearm into that environment. Its a recipe for disaster. Not only for you, but for your roomates.
Personally, I'm NEVER going to trust others around my weapons. I paid for my training with sweat and tears, and unless I know that the "next guy" has been through the same thing, I'm going to assume that he's a blithering idiot when it comes to guns, until he proves me wrong.
This is a good rule. Say it with me now: "EVERYONE ELSE is a blithering idiot when it comes to firearms". LOL. Believe that about everyone who may gain access to your firearm, unless you have sufficient reason not to, i.e., they are law enforcement or military with experience. Even your best buddy who shoots a squirrel gun may not be familiar with handguns.
If you go back to the thread that was closed, I posted a picture of an extendable baton. This is perfect for your needs. Not every problem finds its solution with a firearm. Being able to understand that is the first step towards mature and responsible ownership of a firearm eventually.
I happen to know for a FACT that the D.C. Park Police SWAT team carries these, and many, many Marine and Army MP's and Security Force Battalions carry these as standard issue weapons when on post. I carried one as well. My opinion is they are awesome. And non-lethal. Check them out.