Form 709 – Questions about reporting stocks

This year I gifted a relatively large sum (somewhere in the 6 figures) to my parents. A portion of it was cash transfers on a handful of different dates, and the rest was transferring a brokerage account containing stocks to be in their name.

1. Can I list both of my parents under Schedule A Part 1 (b), or do I need to divide all gifts between the two of them? All deposits/transfers were made to joint accounts in both of their names.
2. For the brokerage account, do I need to list every single stock independently as a different gift?
3. If so, can I list the total cost basis for all shares of a given stock, or do I need to list separately the (many, it would take several pages) different cost bases from the various stock purchases over the years?
4. I got married partly through the year. Some of these gifts were made prior to the marriage, and others were made after. To keep things simple I am planning to not split the gift reporting with my spouse, and only I will file a 709. Is my understanding correct, and there's no downside to this approach other than my lifetime exemption will be affected unequally compared to my spouse?