To be honest, I haven't seen a setting where the logical results of races coexisting where one race lived so much longer than the others was really explored.
In a capitalistic society, the elves would own everything. That might be an interesting campaign setting -- capitalist elves vs communist humans!
Ken
IMC, because elves live for as much as 1000 years, they have very low attachment to any sort of good that doesn't last for at least centuries. Leaving aside the question of whether they really would own everything, you haven't even addressed the question of whether they would want to own anything. IMC, elves would see the question of 'capitalist vs. communist' as one of those stupid petty things that only humans could argue about.
On the other hand, IMC elves would see whether or not you should decorate in the English craftsman style or in the plain Amish style as something worth fighting about and perhaps even killing over. Elves really do have fashion wars.
Secondly, I don't see any reason whatsoever why all property would end up in the hand of elves unless you had a confiscatory inheritence tax, and if you did, then you'd very quickly enter into the main problem with elven rulership. Elves suck as rulers. The problem with elves IMC is sure, they live for centuries, and are on average have several more class levels than shorter lived races but they literally age at about 1/9th the human norm. So it takes an elf like 140 years to reach maturity. Elven pregnancy is like 6 years long. So ultimately, shorter lived races can afford in the long run to trade the lives of many of there members for the lives of one oppressive elf. Elves simply can't afford to engage in any sort of war of attrition, nor can they risk close battle - hense there preference for ambush and ranged weapons. Elves cannot in the long run replace losses.
What makes it even worse for the elves is that compared to other races they have fragile health. Elves avoid cities and live in rural isolation and generally don't keep alot of domestic animals not just because of their attachment to the natural world, but because elves can't afford to get sick. An outbreak of plague decimates elven culture for centuries. Humans can live in filthy crowded cities and work under stressful conditions, but elves just can't risk that. They can't risk any work that has a high chance of death. They can't risk contact with disease carrying races or animals. Isolation is a matter of life and death for them, which is why you rarely see one outside of their wilderness retreats.
The point is that while elves in theory might live for 1000 years, seldom do they get there. The vagaries of chance ultimately mean that most elves die 'untimely' deaths from accidents, disease, and war long before they finish their allotted time span. And, elves for all their intelligence and grace and knowledge, are simply ill-suited to lording over or doing battle with the other races. No matter how many times they win, they are always losing out in the long run.