I don't see the problem here with age. The problem you're describing seems to stem from other social issues, namely nepotism, classism, etc. People living longer isn't going to change that much I suspect; people have had these issues for thousands of years, and if anything, it's much better now than it was centuries ago. There's far more social mobility now than there was in Medieval times.

>Just go to you local city council planning meeting and see how gray haired and crazy the NIMBYs are

I think I already addressed that: age has an effect on the brain, so if we figure out biological immortality, we should also figure out along with that how to eliminate these aging-related problems/diseases.

The other problem you describe there is basically classism, and the ability of locals who gain power to shut others out of power. Again, this was much worse in the past when people didn't live nearly as long. The way to fix it isn't to have people die off early, it's to come up with laws and policies that counteract it.

The way to fix the NIMBYism problem is simple, and they've done something like this in Japan: you remove power from local government to set zoning policy. Obviously, local governments get people like this in power who don't look out for the overall good of society, and instead look to maximize their real estate value through manipulation of zoning, so you strip them of that power and move it to the state or national level. In the Bay Area, this means the state government needs to grow a pair and pass some strict laws about zoning, and severely curtail the ability of local governments to reject development.