| Alexander Augunas Contributor |
If Pathfinder has a flaw, its that multiclassing is a laughable options for many character builds, especially spellcasters. This was mostly an inherited flaw that came from 3.5, but Pathfinder jacks it up to 11 starting with the Advanced Player's Guide classes.
Because all of the witches hexes scale with her witch level and not a value that is shared between class levels the way that all martial characters utilize base attack bonus, the witch's hexes do not progress as you multiclass, meaning that your witch levels are basically dead levels in whatever build you're going for. A hex with a DC of 11 + your Intelligence is not very useful. Compare to the wizard, who only loses a few minor powers for multiclassing; a witch's spells per day and her spell list are balanced around having hexes.
So the short answer is that unless you're planning on going for Winter Witch (which doesn't require you to even leave the Witch class) multiclassing is a very poor option for a witch.