Waajib & Sunnah I'tikaaf

Q: Is it necessary that waajib i’tikaaf be carried out whilst fasting?

Q: If one made i’tikaaf compulsory upon himself, will it be compulsory to carry it out?

Q: Can one sit for sunnah i’tikaaf out of the month of Ramadhaan?

Q: If one's fast broke during the last ten days of Ramadhaan, will his sunnah itikaaf also break? If his itikaaf breaks, will he have to make qadha of the entire ten days' itikaaf or only for the day his itikaaf broke? 

Q: When sitting for sunnah i’tikaaf, is it necessary for one to be fasting?

Q: Is it permissible for a man sitting for Sunnah i'tikaaf to use a cell phone to check on his family at home and to see to their needs?