While Lady Crawford was in the hospital, she emailed Ms. White.
Lady Crawford, while in the hospital, emailed Ms. White.
While overseas on deployment, Tidus reported to his supervisor.
Tidus reported to his supervisor when overseas on deployment.
While Mariah was on vacation, Sarah offered to clean her apartment.
Sarah, while Mariah was on vacation, offered to clean her apartment.
Since Beth had lost her watch, she and Melissa were both late.
Melissa and Beth were both late, since Beth had lost her watch.
As we settled in to the new ship, tension began to mount. Emphasis on “tension began to mount.”
intents and
In this sentence "intensive" is used incorrectly. Intensive means very concentrated or focused on a specific subject. The sentence should say "for all intents and purposes". This does repeat the idea of purposes because someone's intent is their purpose, but that is the correct phrase that is commonly used. It comes from 16th century English law and means "in every practical sense".