A: If you are in a lease you are obliged to fulfill the terms of your agreement. If there is a dispute you can arrange to have it arbitrated privately, or through the Residential Tenancy Branch. If you try walking out on the landlord with several months left on your lease you can expect him to chase you for lost rent, debt and damages, and probably a few other things he'll think he has an outside chance of getting. Trust me, stiffing the landlord is often the most expensive and complicated option a tenant can choose. It gets ugly, quickly.
If you are convinced the premises are unlivable, it would be unconscionable to try foisting it off on someone else. My advice is to write the landlord a letter detailing what your complaints are, what you want done, and by when, and explaining that you are thinking of launching a claim in arbitration if his response isn't satisfactory.