1) "So how do I allocate?"

You look through the million pages of 1099 detail and figure out what specific qualified dividends foreign taxes were withheld from. I initially thought that cursing the broker as I worked would be helpful, but billing the client for the extra time needed seems to make it less miserable. (I upgraded my version of Acrobat this year, too, and exporting the entire thing to Excel and then manipulating the relevant rows is less tedious than typing the numbers by hand.)

2) "I would assume that I put 1088 in the "percentage foreign or amount - total ordinary" field, but when I do that the numbers on the 1116 do not match the actual amount of foreign dividends!"

You also need an amount in the qualified and capital gains distributions fields directly below that one. If none, enter -1.

Don't forget that the IRS currently wants everything broken out country by country, too.