In general, the biggest problem with converting adventures to the Scarred Lands lies in the Druid/Cleric dichotomy and the spells available to each, and to a lesser extent, the Wizard/Sorcerer split.
For example, if the villian in an adventure is an evil cleric and you want to make him an evil druid to fit the SL theme, you have to get rid of all of his Glyphs of Warding. On the flip side, one of the neatest things about the SL is how Good and Evil will team up to stop Titanic, so not every "evil" cleric would be your enemy, and it would actually be a victory to have an evil cleric convert a horde of orcs, because that's less titanworship left in the world.