Well, it looks like you're going to surrender your share of the booty. Don't you like booty? Everyone likes booty! Go back and fight for your late dad's booty! Wait...that sounds wrong.

Ugly, ugly scene and a dysfunctional family… Unfortunately this sort of thing is not that uncommon. I was fortunate that there was a minimal level of this with my Dad and Grandparents. You have to make a value judgement - Is the potential inheritance worth fighting over for you or not? And it doesn’t have to be a high monetary value - It might be an artifact of some sort that has a special meaning for you. Figure out what matters most to you - Staying out of the arguments or getting something that is important to you. Whichever way you go, be fair but stick to your decision. This is a prime example of why people need a will or even a simple (signed and dated) paper saying who you want to get your stuff when you pass. After someone dies it’s a difficult time at best and these things can get ugly fast enough if there is a conflict. I am very glad I have a few personal artifacts from my father and grandparents. They don’t have much monetary value, but looking at them or holding them in my hand transports me back in time to the happier times I spent with them.

Sounds like you're well rid of them.

make sure they don't cheat you out of your share of the inheritance

Best to stay out of that kerfuffle and let the vultures fight amongst themselves. It's a shame you had to waste time and money driving into that mess, but at least they've shown how not to behave.