Along with most of the other more or less rational people giving you good advice in this thread, I suggest that you eschew violence while you can. Since you’re the one considering its first use, then obviously “you can avoid violence”. In that case, do that.
There are several reasons to avoid violence. From a practical standpoint, as at least one respondent has indicated, if you start a fight how likely is it that you will be the one standing after it’s over? You don’t want to be a martyr to a silly cause like this. And it is a silly cause, no matter how serious it seems to you right now having to live through it.
Another practical matter to consider is what happens if you’re “victorious” in a physical confrontation? Your roommate will be able to appeal to all sorts of authorities (not the police, if she so chooses) including your landlord and your own father and claim, justifiably and honestly, “She started it. She attacked me first.” At that point your victory turns to sound and certain defeat.
Nor should you threaten violence (or any other action) that you’re not fully prepared, willing and capable to carry to a conclusion. What if you start a fight and she escalates it? Are you prepared to kill over this squabble if that’s what you have to do to save your life after you start a fight? Are you prepared to be killed if your roommate is an unbalanced sociopath?
So violence should be off the table. (Never hesitate to defend your own life, but never choose violence if you don’t have to, either.)
Don’t also consider yourself “locked-in” to your current living arrangement. If your apartment burned down, would you still have to live there? If you broke your leg, would it be reset in your apartment? If you choose violence and someone (anyone) sends the police, who determine that you started it, will they lock you up in your apartment? No, of course “no” to all of those rhetorical questions. Leaving the apartment is an option. If it’s not a desired option for you, perhaps you can make it a desired option for your roommate. How much money would you need to offer her to make her go away? It’s worth consideration. In the bigger picture, a $10,000 cash payout (if that’s what it takes) is cheap compared to the cost of an attorney, trial and permanent criminal record for the rest of your life.
But that wouldn’t be my first choice, either – although you do need to change your mind about your “locked-in-to-this-and-can’t-move” mindset.
My first choice would be to force a conversation upon her, even if she’s snarky, snide, resentful (over what?), sarcastic and bitter. Even if it’s a conversation that’s unpleasant to you. TALK TO HER.
When all else fails, you can send a letter to the landlord (an attorney should help with this) detailing the “unsafe and illegal acts” which he refuses to even attempt to correct, and stating that this material breach of your rental contract enables you to leave without penalty. Definitely pay for an attorney to write the letter (and review your lease). He or she will know exactly what needs to be said, and you can probably be out of there in a week or less.