"My /home partition was fine. If I upgrade using a mint 14 iso will the upgrade be so smooth, or will it wipe my /home partition?"
Depends did you originally create a separate partition for /home? if so then you are fine as did a 13 to 14 and just pointed the install to my /root partition as /home was separate and safe. But the biggest concern is jumping 2 versions is breakage on installed apps and may find a few that need to be upgraded or reinstalled depending on the app of course.
As a Clean Install especially skipping a version is the best course of action.
And I would think it would take a lot more time trying to go to 13 then 14 upgrades install would take hours to do? And a backup your home and clean install and restore /home about an hour to hour and a half.