The question is unclear. There is no offline Hajj.
He performed Hajj only once in his life. Hajj is obligatory on Muslims just once in their life time.
according to Islamic laws yes can. rules of Hajj are for during Hajj started by becoming Muhrim (included in Hajj) in Shajareh mosque at mecca. and before becoming Muhrim there is no problem breaking rules of Hajj.
one hajj in his whole life
No, you do not have to go bald before performing Hajj. It is a common practice for male pilgrims to shave their heads as a symbol of humility and renewal during Hajj, but it is not a requirement.
Islam believes in life hereafter and the Day of Judgment. Hajj is the firth pillar of Islam.
The hajj wasn't built... the hajj is a pilgrimage to Makkah, to now rebuilt/ improved buildings/ region which were there before Islam.
Those who can afford it physically, financially, and safely.
The Prophet p.b.u.h. had performed a Hajj before he died.
they used to travel on animals camels horses ... etc some of them had to get going 3 months before Hajj to get to Makka by the time of Hajj
At least one day before Hajj, i.e. 7th of Zil Hajja.
Although Hajj is not compulsory on children but they are allowed to go for Hajj. Hajj is compulsory, for once in life, on the adult mindful Muslim (male or female) who can afford doing it fimancially, physically, and securely.