There are many sound hadiths which urge the Muslim to recite du`as for good health and protection from harms and ills such as “Allahumma inni a ‘udhu bika min al-barasi wa’l-jununi wa’l-judhami wa min sayyi’il-asqam.”

With regard to du'a for entering the house, one should mention the name of Allah, remember Allah and give the greeting of salaam, even if there is no one in the house. For more, please see the detailed answer.

There are so many sound du'as that you can say before sleeping that were narrated in the Prophet’s Sunnah. For more, see the detailed answer.

There are many authentic hadiths about morning and evening adhkar. See the detailed answer for some of these narrations.

There is no report from the Prophet (peace and blessings be upon him) concerning du`as and adhkar to be recited in tawaf. You may offer whatever supplication you like or recite any dhikr.