Carrie,
Sir George Foreman...aka Butch was given to me when he was approximately 9 months old...now 3 yrs. When I say given, this was a unique circumstance as he was owned by a widowed lady who had purchased him from a breeder, and for some reason "could not handle him". Rumor has it that she often hit him. That said, we attributed some of his behavior to his association of her with my wife.
He has a crate but we most often let him sleep on the couches and yes we have a doggy door which allows him free access to the backyard. Bulldogs by trait are not overly active...and Florida is "hot", thus he spends most of his time indoors.
No free access to food. Fed twice a day a.m./p.m. in conjunction with my other dog...again not food possessive. (My wife is now in control of his feeding)
Dogs are left together, alone, when we are not here and they do fine together...Butch's behavior seems to manifest itself in the evening hours when he seems to be tired and/or, as mentioned before, when my wife enters the living room from the back or when she is leaving the house with purse or package in hand.
My other dog show his anxiety when Butch exhibits this "tired" behavior, (He seems to sense it). Interesting is that in the morning or during the day when they are outside they "play/roughhouse"...without problems.
Butch is "my" dog..likes to be near me and we are associating some of this behavior with what might be jealousy.
Hope I have answered your questions and thanks for your interest.