Short answers, pulled from the story.
Paul I of Russia died on the night of the 23rd of March 1801 after being struck with a sword by Nikolay Zubov and strangled to death by conspirators. The assassins attempted to force him to sign abdication documents before killing him while hiding behind drapes in his bedroom at Saint Michael's Castle.
Paul I of Russia ordered the Imperial Russian Army to wear impractical Prussian uniforms instead of comfortable Russian styles introduced by Grigori Potemkin. He dismissed seven field marshals and 333 generals who refused to adopt his chivalric vision of military service which emphasized show over practical combat readiness.
Paul I of Russia closed all British factories in St. Petersburg and impounded every merchant vessel carrying cargo through Russian ports after Britain captured Malta without returning control to the Order. He froze all trade between Northern Europe and Great Britain during the winter months of 1800-1801 to force compliance with his demands regarding the island.
General Levin August Count von Bennigsen and General Vladimir Mikhailovich Yashvil led a group of dismissed officers into Paul's bedroom at Saint Michael's Castle to kill him. Nikolay Zubov struck Paul with a sword before other conspirators strangled him while court physician James Wylie declared apoplexy as the official cause of death.
Empress Elizabeth took Paul immediately after birth and left him to the care of others while she pursued her own interests. Catherine kept Paul at a distance allowing him only brief appearances at court functions while she focused on her lovers and political allies until granting him Gatchina Palace by 1783.