“First, his secretary’s taxes include paying disproportionate (relative to the salary) in payroll/Social Security taxes, which is capped and therefore is a miniscule percentage on $39M.”
Aren’t payroll taxes in fact taxes on income and therefore “income taxes”? So make it fair and undo the cap. That would bring the tax rate that Warren Buffet pays into line with his employees.
No, they are specifically not general-purpose "income taxes," they are taxes that go into mythical Social Security Trust Fund (which are of course, appropriated and spent by the general fund by way of IOUs).
So make it fair and undo the cap.
You seem to have a strange idea of "fair." Social Security taxes are for the individual retirement, and that's the reason they are capped. In fact, Obama had suggested and passed into law a "payroll tax break" to "stimulate the economy" and is now proposing extending it, which for some reason Republicans in Congress oppose (possibly, fiscally responsible toward Social Security, but a loser politically, just like Paul Ryan's Medicare reform proposal within the budget reform fight). To make Social Security mandatory withholding tax uncapped would make it just another general-purpose income-transfer tax, which it was not designed to be and is unconstitutional (not that it would stop politicians from trying).
To do all this, just to make it "fair" to the likes of Warren Buffett would only penalize middle class even more, it's the same as the idea of "means-testing" for Social Security "benefits" so that the program can be "saved."
That would bring the tax rate that Warren Buffet pays into line with his employees.
Not in the least. You probably missed the part about lower rates on capital gains tax (which is not, in fact, a regular "income tax") that is the bulk of Warren Buffett's annual "income." His staff is receiving salary, which is subject to regular "income tax" and capped "payroll"/Social Security/FICA (Federal Income Contribution Act) tax, his capital gains "income" do not (and should not be. Capital gains tax is also taxes at lower rate, to compensate for the investment risk of total loss (many quite reasonably think that it's double-taxation already on earned capital and the tax should be eliminated alltogether). Buffett also uses "charitable donations" to significantly lower his tax rate, which few of his staff can utilize with the same effectiveness (Law of Large Numbers).
You don't seem to understand the difference between different taxes, and why they might have different rates (incentives, disincentives, penalties, so-called "loopholes" etc.) There is a reason why Warren Buffett has many tax accountants and lawyers and his staff don't.
If you stop trying to fit higher taxes on everybody as the means of being "fair" or the "solution" to government deficits and government looking for higher revenue, it will become easier and simpler to understand what you seem to have missed about tax "fairness" in my two previous posts or how much easier it it for the "rich" to not having to pay "income" taxes just by deferring the "income" into the future years or moving them into legal tax-free havens such as munis etc. They can live for awhile off their wealth or from tax-free income or free up some money by firing the "staff"... can the typical middle-class "staff" do that?
That doesn't even count the numerous taxes and fees from the states and municipalities. Look again in the first post at how much of federal tax revenue burden falls on the 1%, 5%, 10% of top earners and then decide if that is their true "fair share" or do they need to "contribute" more to the government that thinks it can spend them into "prosperity"?