1) Fair enough, but on the whole the Federalists and Whigs were more antislavery than their opponents, I think you'd agree, owing to their bases of power in the Northeast, even if there existed many individual pro-slavery Federalists/Whigs and antislavery Republicans/Democrats.
How do we have 11 pages and you're still sticking to this absurd point.
The Whig Party was not a northeastern party with a several pro slavery characters within it. It was an overtly pro slavery party that blamed anti slavery agitators for the disturbances in the country, and went out of it's way to portray itself as a national party, not a north eastern one.
The Whigs were not significantly more anti slavery than the Democrats in any
real way. They nominated a pro-expansion hack twice (William Henry Harrison) against a future Free Soiler (although MvB is hardly an icon of the anti slavery cause), it was a Whig President that signed the Fugitive Slave Act! Where did the Whigs actually meaningfully oppose slavery more than their opponents.
Sure the Whig Party had Lincoln and Seward (although, case in point, Seward was inferior in his influence in the NY Whigs to the likes of Fillmore), but it also had Alexander Stephens and Robert Hunter. I really fail to see how it was meaningfully more anti slavery than the Democrats.