Best Answer - Chosen by the Asker
行动 is more like you have a plan, you have a target to achieve
採取行动: take action
it can also be used as "the ability to move"
行动不便： unable to move freely due to the health problem
动作 i think is the most general term for movement, it's often used for body movement.
他打球动作很好: his movement when playing balls is quite correct/standard.
举动 to me is always used when someone is watching
監視他的举动： monitor (his behavior)
如果他有任何举动，馬上通知我： Inform me if he has any slightest movement
行為 is behavior
不當行為: improper behavior
