I'm going to blare my alarm really loud in the morning to make my flatmate as sleep deprived as me
Why do you want him to suffer as you are?
He is a bastard and I hate him.
It sounds rough to live with a flatmate who you personally dislike and I've been through that same thing before. One of my friends was telling me a story about how he started messing with his flatmate and then things progressed so bad that they both had to move out, is that what you think might happen here?
I don't care. I'm going to do it to spite him.
If you make him miserable, then he is probably going to retaliate and you will be stuck in a cycle. Easier to let things go and move on.