Lee get your self a new pet,The rottweiller apparantly is very teritoriaL, i know this because i have one
yes they do crap a bit and you would need it to run around the outside and not inside due to your alarm system,it also has been know for these dogs(and i DO NOT condone this kind of thing) for them to have their voice box removed ,this way they do not bark,silent but very deadly, this is the way forward for peeps in your position i believe