Some of them (such as the plan to invade either India or the Ottoman Empire during his Egyptian campaign) were clearly just idle musing, but were any of them ever serious, and if so could any of them feasibly have worked?
Beyond the Egyptian Adventure, it was nothing but idle musing. In respect to how his coup and subsequent Imperial reign, Continental Europe and France's European enemies took far more attention than a land invasion of India to punish the British.
Further, I would argue even further that the creation of the Continental System (created to ruin the British economy) was meant to take place of an Indian invasion since that was a more feasible method of striking British trade.