بسم الله الرحمن الرحيم
During itikaf it is allowed only to go out of the Shariah mosque to have ghusl janabat. It is not lawful to go out of the mosque to get coolness or have ghusl for Jumuah, it shall nullify the itikaf. It is not lawful for the motakif to go out of the Shariah mosque. If he wants to have necessary talks then he should do it within the limit of the Shariah mosque as itikaf shall be nullified if he goes out of the mosque.
(2) It is necessary to maintain many things during itikaf, for details read some related book for example: Adab-e-Itikaf, Itikaf Ke Fazail Wa Masail, Ahmak-e-Itikaf etc.
Allah knows Best!
Darul Uloom Deoband