There is no 10% penalty after age 59½. Had your code B distribution been subject to an early-distribution penalty there would also have been a code 1 in box 7; TurboTax goes by the code 1 to determine whether or not the taxable amount is subject to this penalty.
The year indicated in box 11 is only for indicating whether or not the distribution is a qualified distribution, but TurboTax should be going only by the amount in box 2a to determine the taxable amount, if any.
When I enter the code H Form 1099-R second or later I see the first problem that I mentioned, a problem that seems to be separate from the box-11 problem. I've reported both of these problems.
Yes, if the Form 1099-R does not show tax withholding, TurboTax will not include the details of the form in your e-filing and the IRS will be unaware that you omitted the box-11 entry.
Note that the 5-year rule for your Roth 401(k) is similar to but separate from the 5-year rule for your Roth IRAs. The 5-year holding period of the Roth 401(k) does not carry over to the Roth IRA, so the box-11 year has nothing to do with determining whether or not your Roth IRAs are qualified. As I mentioned, the box-11 year is only needs to be used by TurboTax to determine how much of a rollover from a Roth 401(k) to a Roth IRA is to be treated as contribution basis in the Roth IRA, and TurboTax does not handle this function properly either (and it never has).
