considering a dog adoption, but some bad habits

Question
i am considering adopting a 5-yr old spayed "mutt" about 25 lb.  she seems very sweet, but she demonstrated some bad habits when i met her.  i am not a very experienced dog owner, and so am not sure how difficult this might be.  when I first met her, she peed on the kitchen floor from excitement and was having trouble not jumping up.  we went for a walk and she pulled a bit, which i think can be overcome, but she barked whenever a car passed by on the street.  i work from home and would be with her most of the day most of the time.  the owners are getting a divorce and she needs a home, but i didn't have a feel for how difficult it would be to discourage this excited behavior and encourage a more mellow outlook on life

Answer
For some questions, my head says one thing, and my heart says another.  First of all, you might see what some of the people here with more experience with older dogs have to say.  Correcting problems after a dog is 5 years old requires a different skill set from getting a dog off to a good start where most of my training and experience lies.  We do have some good people here, especially in the dog training area.  Just read their profiles carefully and try to choose somebody with some substantial experience and training.  There are those here that are little more than average dog owners and are not giving very good advice.  

While those problems are all correctable in a younger dog, it could take extensive time and work with a 5 years old.  Logic tells me we are slaughtering dogs by the million every year, and you should look around for an easier one.  Those ruled by logic, wouldn't have a dog at all.