Its a mess

Question
Me and my boyfriend living together in the same appartement,we r students at the same university and we have a 4 monthes golden beautiful lab.we taught her sit,no,quiet,couch,go home(crate)..the problem is she is intelligent but very stubborn,sometimes she listens,sometimes not(we r using treats)and when there's strangers&others dog or pets around,she goes crazy&dont listen at all.sometimes she listens to strangers when they tell her orders like sit,no..!we dont want her to obey strangers,i want her to doubt in them,and let others to be scared from our dog!i want to walk her without the leach like any other great dog.but i cant,she start running over the garbage!we r housebreaking her by the crate training.everytime we catch her in the act she continues peeing,sometimes i have to hold her and take her outside,that she continues peeing on me!she ignores us!once she shit in the crate,when we went for 2 hours,&everytime we dont take her out with us she shit&pee on the floor!(although she has her own time to go out)everyday we clean the house like 4 times!we r hitting her on the nose gently to know she is mistaken when she doesnt obey!she get scare when a dog bark,then she ignore his barking..is it a courage attitude or weak?we got her toys to bite,but she likes biting hands and legs as playing.we want her to be a great courage female,obediant and not at all to strangers or friends,we want her to attack when we tell her,take her out without the leach!i want her to be our guardien!plz help me,tell me how and release me from cleaning everyday!by the way,is it possible 2 persons to be her masters?however how can i be her master(not my bf:P) and gain her trust?
thank u  

Answer
This is too complex for me to try to answer it here.  You need to be working from a good book, maybe the Monks of New Skete's The Art of Raising a Puppy.  Even carefully following everything in it, you may never have a protective dog you can walk without a leash.  Some dogs just aren't that way.  

Most dogs tend to bond more strongly with one member of the family.  As long as both give it plenty of attention, the dog should work well with both of you.