Such a sleeping arrangement may not be possible in your circumstances. Parasomnias include night terrors, sleep walking, and sleep talking. You state your son talks, fights with siblings, and cries during sleep. If he appears to be asleep during all of this, he could be having nightmares or he could be sleep talking. These points may help differentiate the two states.
Sleep disorders are more common during stressful life circumstances.
This is especially true of nightmares. Pain in one leg is less common and this deserves review by your pediatrician. As mentioned above, pain of any source can exacerbate sleep difficulties. I hope this review and these suggestions prove useful to you. This information is provided for educational purposes only.