I am so very sorry for you loss of Chance. It sounds as though he had a wonderful mommy that loved him very, very much.
I am glad that you were willing to open up your heart again to love again. I can only imagine what you must be going thru but don't look for somethng that may not be there. While your vet and you suspect liver shunt, don't drive yourself crazy until you get results back. As for the Honda and his surgery, I've read of successful neuterings of that type here on YT.
My Maggie honks as well and she is perfectly fine beyond that. You can use your finger and hold his snout downward towards his chest and this will open up his airway and the honking will stop instantaneously.
It sounds as though you have already bonded with these little guys. Don't look for trouble, just keep your heart focused on them. It is never easy to thnk of the prospect of losing a beloved pet as they are your family but if you focus on the loss, you will never know the joy. Unless you are willing to give these 2 up for new puppies, then I would just concentrate on dealing with each of their issues from day to day. I will be keeping you and your little ones in my thoughts and prayers that you get good news with the vet. Please keep us updated.
p.s. Welcome to YT and Happy Birthday.