ISIS is fighting to gain control of the Kobani region in Syria, which is important strategically, but Kurds are trying to keep it in Syria's hands.
如果把句子中的strategically，
改为strategy。
文法对吗？
若对，意思有变吗？
谢谢

如果要改成strategy记得要加冠词 "an"。

意思变了. K是重要战略据点被改成:占K在战略上很重要

which代"ISIS is fighting... Syria"整句意思就没差吧?

which代那整句 有可能Kobani这地方本身不重要 是"攻占Kobani"这个行动重要(分散敌人兵力之类的)