Re: Advice on "how" to leave
I hope you're okay.
The POD idea is a great one - you can set up a PO Box that he knows nothing about to start switching your mail, and most of your accounts can be set to paperless. PODs will store your stuff indefinitely, and it won't be prone to his rages.
I would also switch my bank accounts and card numbers - all of them, because he may have some slip of paper that would give him enough information to cause trouble. Set all of the addresses to the PO Box, and keep the key to that box at work or a friends.
Get the utilities out of your name - tell them you are moving and you don't know where to, but schedule the date for termination. You don't want months and months of duplicate billings for two places.
Start squirreling money away to take a long vacation when you move. Get your stuff into a POD, and if you are not at work, he won't know where to look. Go to a different state for some rest. Tell your work that no information is to be released about your whereabouts or work status, even if they are family. Come back in time to set up your new place before returning to work.
Tricky - Get the Pot out of your house any way necessary. He may say it is yours and that you are trying to blame him. Even if he doesn't, it can still be used against you to seize any assets you may have. One suggestion - Call twenty friends - I know these types isolate you - and ask them to help and support you in this separation. Put all of the pot in his car and tell him you're calling the police in five minutes - he has five minutes to get it off of shared property. You won't call the police if he goes quietly. If there's twenty of you standing around, he's unlikely to attack, and if he does, he'll be the one that's worse for the wear.
Whatever you do, don't call the police to help you remove the pot. You may be held responsible, because you may have assets that can be seized. Also, though I love good cops, there are bad ones, and you never know what you will get coming to your door. A conviction has to happen for seizure.
Empty every booze bottle in your house. Whatever you do, don't give him money.
You said it could be considered abandonment of your home - so talk to your landlord. Tell him your willing to pay three month's rent over time until it is paid off, but that you cannot live in this hostile environment. The landlord may be willing to help evict him in some way. The goal is to move away safely. Really, you don't want to be in a place that is familiar to your bf. If he doesn't know where you are, he can't show up at all hours demanding to be let into "his" home.
The dog - there are rescue places for pits, and this poor dog sounds in need of a rescue. Explain that you cannot protect the animal from your bf, and tell the bf it must have ran away when you woke and found he left the door open in his drunken stupor. Work it out with a friend to pick the dog up one night and take it to the rescue the next day.
All of this may seem like a lot to do, but it is a matter of regaining control of your life. You may not need to be this extreme, but I tried to list suggestions for an extreme situation. This man has manipulated you into a sticky situation, and he won't help you get out of it. You have to help yourself.
Take care, and remember, he is not a friend. He is a manipulative user.