But i will be 60 when my father hit 80, and my child would be 30 (actually 29).
The life expectancy of men is 79.4 yo, and while he's a woodworker, he actually is healthy for someone in his 50 (and he's doing a lot more painting and tapestry now, which is easier on the body), so i hope he won't die until his late 80s, but let's say he only last until 80.
At 60 year old, i would expect to retire two years later (might be 4, but let's wait and see). Anything that he leaves me, i wouldn't really need. I would rent his house (maybe, i think i would just lend it to a non-market housing coop), but hopefully i would have one at that age. My child at 30 would hopefully have found his path, since i have enough resources for him to fail a dozen time.
Even if i die at 60, i really hope my child doesn't need my money, because that would mean i had failed him a dozen time over, don't you agree?
But let's say we just put a small limit, let's say 20k in 1970s dollars (to adjust for inflation), that would still remove the need for income and housing taxes in my country. tax collection would be more efficient, that would pay for the most basic social nets + free education (and police, and military), and the only taxes you would pay on income wouldn't be taxes but cotisations (health, unemployment).
Also, not only education basically free, i have family that is nice and helpful, and even if i die tomorrow i don't care if all my money had to go to the state.
And for those who do not have this family, i would hope that if inheritance tax is the only tax, each orphan would get the same treatment as nations'pupils (orphan from military or police, i worked with them 3 summers a lifetime ago) and taken care of better than they are right now.
[edit] And because i don't want to be too obtuse (i honestly didn't understand you until now): of course if you live in a low-trust society, it's a bad idea. If i were Indian or from an emmerging country, i wouldn't think this. To me, capitalism and the pursuit of individual wealth is the best vessel to reach a high-trust society (basically what marx said), and once we're there, we can shed id, we do not need it anymore. That also mean that, unlike Marx's Internationale, i do not believe each society can get there at the same time, and high-trust societies have to enforce immigration quotas from low-trust ones (to respond to your "no border" comment).