Sleeping throughout the day whilst fasting

During Ramadhaan, if one was to take the pre-dawn meal and pray the Fajr prayer, then sleep until noon and prayed the Dhuhr prayer after which he would sleep until Asr, then pray the Asr prayer and, again, sleep until the time of breaking the fast, would his fast be correct?

Assumed the use of the miswaak had broken his fast

A man used the miswaak whilst fasting and then assumed that this had broken his fast, so [because of this], he drank and ate afterwards. So, is it obligatory upon him to make up this fast and offer an expiation or [is it sufficient] just to make up the fast?