He will take patience, but will be so worth it! The tire drag is a good idea, wouldn't work for me because of too many trees that my husband is in love with and won't let me cut for more pasture. Murphy is going to make you one fine dog. Have you considered neutering him? It might take some of the attitude out of him, before it gets to be solidly entrenched behavior. My two, Sentry and Carson still have theirs and they are getting ugly to each other. Wrong thing to do dogs, it is snip, snip time.
I'm so sorry about your Dad. I know he has not been in very good health for a long time and it may come as a relief, but is still sad and will leave a gap in your and your Mom's lives. I was with my Daddy when he died and I cried tears of relief for him that he would no longer suffer. It's been almost 30 years and I still miss him. If you can, take a little time for yourself. A quiet moment in the pasture with the sheep is the best medicine for a broken heart. Big hugs to you.
You got a lot on your plate right now, and it will continue for sometime. Lots of work ahead getting ready for winter. Add the things to be done after your Dad's funeral, the paperwork and legalities can get absurd. My prayers are with you.
Thoughts and prayers for you. My parents health has declined greatly and my mom has dementia/alzheimers or something they won't put a label on. Family dynamics being what they are, my one brother is "in charge" of their care and all. Stopped trying to fight them so I stay at my distance. I butt heads with my father terribly as we are too alike. So it is better for all concerned to keep my distance and offer what I can even when it is totally rebuffed by the brother.