Why does "Student Information Worksheet" for a 529 withdrawal, Part VIII, column "For Purposes of REgular Tax", line 2f only reflect room + board, and not tuition?

I haven't heard of any complaints or issues in that area. Maybe you don't need to enter the 1099-Q and don't need that section. 

IRS Pub 970 states: Generally, distributions are tax free if they aren't more than the beneficiary's AQEE for the year. Don't report tax-free distributions (including qualifying rollovers) on your tax return.

If you do need to enter the form, please reply with more information regarding the 529 numbers, 1098T information, room and board, etc.

You should not enter room & board as qualified expenses for elementary and secondary (high school) education. Enter tuition only.