I'd have a single tax for income. No estate tax or payroll tax, Gifts and inheritances would also be taxed to the recipient as income, although if they were large I think they should be able to allocate the money over several years for tax purposes.
As for the rates, I would make it steeply progressive. Everyone making under $100K would pay about as much as they do now (minus payroll taxes), while tax brackets would increase from there so that people making >$10 million/year would pay about 90-95% of their income above this.
Excellent plan NickG!
As for Philip, he doesn't understand his class identity.