Very quickly on bequests, I used to be an estate planner prior to joining the academy.
A useful first step might be to take a look at what donations out of testamentary trusts created in wills are actually recognized as gifts. The way the law currently stands, many distributions of income out of testamentary trusts do not qualify as gifts. Many distributions of capital out of family trusts created under wills do not qualify as gifts, and there's the potential to lose out on billions of dollars.
That might be a bit of an exaggeration there, but the point is that there's going to be billions of dollars of wealth transferred through trusts, and there's the potential that a bunch of that won't go tax-receipted. That's a serious problem.