I could be wrong, but I don't think you can be held personally responsible for his debts, taxes, etc. You probably weren't responsible for his transport and cremation, except the state would have done something and you might not have liked what they did. Creditors might be able to go after his "estate", I dunno.
I don't know of anything that says you have to write an obituary or have a memorial service, unless you just want to.
It might be worth talking to a lawyer. A company that handles estate sales might be able to help with evaluating and selling the valuable possessions, they will of course take a percentage but get it done a lot more quickly and better be able to research value so as not to sell something WAY too cheap.
If you find any nice guitars in the piles I might be your huckleberry.
Just kidding, I really need to start playing the ones I have more.
I felt overwhelmed at times with my wife's and mother's final arrangements, and it wasn't even a small percentage of what you've been saddled with. I'm so sorry you have to deal with this!
Aries
~Sign of the Rams