box 1a and 1b are not used in the FTC calculation.
box 6 is for investment expenses that aren't even deductible anymore.
what seems to be missing if the FTC is over the limit is form 1116 along with that you need to specify the amount of foreign dividends included in box 1 on line 7d and the country in box 8. without 7d you have no foreign income and get no FTC.
you may also have to complete the questions for the alternative minimum tax foreign tax credit
I admit the last 2 examples do not make sense except if AMT is involved (form 6251).
