And I'm done reading the whole thread now.
My Mom died almost 5 years ago. She owned a business that we sold, but then had to deal with 7 years of unfiled and unpaid personal and business taxes. The estate took over 4 years to settle, and the only things she owned were the business, and 2 vehicles (no real estate). It was crazy difficult, and required three trips to probate court with the estate. We had to hire an estate lawyer, and a tax lawyer to deal with that mess.
I burned through $60,000 pretty quickly (a few cars, and the start-up costs for my business, our wedding, paying for the remainder of DH's and my school, a few vacations), despite being pretty financially-savy, and we are in a higher cost of living area, so our house is the most expensive thing we've bought. We only owe ~$65,000 on the house (less than 20% of the cost).
I'm not sure that my life is any better than it would have been, if my Mom was still here, and we'd not received a penny. She was TERRIBLE with money (as evidenced by her non-payment of any taxes in 7+ years before her death) and if she'd had access to the money, she'd likely have spent every penny herself. My life is different, that is for sure. We didn't have the best relationship (she was emotionally abusive) and it took me a good 3 years after her death, to process it all.
Anyhow, it sure 'set us up' as our housing costs for our family-sized 3 bedroom house, are just the same as they were for our 1 bedroom apartment, because of the cash we put down. I am grateful, while at the same time, still battle with the guilt of enjoying the freedom that her death brought (both monetarily, and emotionally). I miss her less and less, but often it is more intense than I expect it to be.
My Dad will be retiring sometime in the next few years, and I hope he lives until a ripe old age, free of mental and physical limitations. I haven't talked in detail with him about his finances, but I saw the other day that he's keeping 10 times what he should be, in cash, in his chequing account, and I gave him crap for it being there, and not being somewhere earning interest. He's old school though, and feels like he always needs access to enough to pay cash for something large (like think brand new car large) over a weekend. His GF is working on getting him to use online banking, and then we can get him an e-savings account that he can have the access to he likes, while also earning interest.
We paid off his house with the first estate disbursements, and he owes no one, any money. He has both of my Mom's vehicles, and he has such a large FU fund, that he often reminds his employer, who is really in charge in that relationship (go Dad!). He used to be the kind of person who never took more than 4 vacation days a year, and saved every penny for later. However, since my Mom's death, he has finally started spending money on things he wants, and he enjoys, like trips to Nascar stuff. He takes at least a month off work every year, and heads south.
I hope that he, and his money last the exact same time, but I suspect that he is frugal enough that his money will outlast him, and there will be something left for us. Hopefully that won't be for another 30+ years though. I don't think I can handle losing another parent yet.
As for the inlaws, it is a completely different story. My FIL will likely never be able to retire, but will somehow be financially independent. However, my MIL will likely need our financial support, and will probably wind up living with us in the future.
DH and I would like to be able to pay for schooling for our kids, should we be blessed with them, but we won't likely tell them. I grew up in a frugal household, where we bought things secondhand, and I worked for my activity money (paper routes and the like, starting when I was 8). I grew up knowing the value of a dollar, and we want our kids to be the same way.
I'm not sure that I really answered the question, but I didn't expect to inherit anything, until my Mom died suddenly almost 5 years ago, and I'm not expecting anything else, as my one set of grandparents are likely to leave the bulk of their (likely sizeable) estate to my uncles that run farms.
Money changes family dynamics, and not always for the better. I think my family is rather unscathed, but my inlaws definitely treat us differently than they used to.