The buses are NOT that bad, especially if you get stagecoach (which if I'm right, is only a pound more than getting magic bus - per week). Magic bus are rank at 9am and if you're hungover having your face in someones back/face/armpit is not nice. But, if it was really that bad, the majority of first year halls wouldn't be in Fallowfield.
Try north campus (Weston, Chandos), it's quieter and you can walk to Law (Brunwick Street, Williamson Building I'd imagine the majority of the time) in about 15 mins, 10 if you walk fast.