How buddha came back to his human consciousness if consciousness and fabrication ceases after release QN 1: After complete cessation of consciousness, how did the Buddha come back to human consciousness?
If he can come back, isn't it not a complete release?

And that state is just like the Dimension of Nothingness, or the Dimension of Neither Perceptions nor Non--perceptions. So if craving again develops, then there may be chance of becoming. 

 
QN 2: And is it possible to have complete release through jhana only by ceasing craving, fabrication etc without gaining insight of nirvana.

QN 3: Buddha stated in many suttas that five aggregates are not-self; but as human being we do require idea of self (identity or ego) and will power (self-esteem). [Like, "If I try I can learn it or do it etc"] . Is there any sutta where buddha talked about such healthy ego? [Here ego word does not mean pride, conceit etc but Identity.] 

Note: Buddha avoided such type of questions because this stop us from direct knowing, but I am asking due to curiosity. But do reply for third question. 


Edit: I think I found the sutta for healthy ego (Identity).  AN 5.57
 
I was not asking about 'self' or 'no-self'. I was asking because it's help us psychologically and even Buddha used to call himself Bodhisattva (Who thinks about well-being of everyone and has compassion towards all.) before awakening because it's remind us about our path. 
Also there is one video I found helpful. 


  https://youtu.be/w7irEcQHChw?t=1h08m32s 


"I updated my last question because I think it was creating a little confusion."
QN 1: After complete cessation of consciousness, how did the Buddha
  come back to human consciousness? If he can come back, isn't it not a
  complete release?


Well, there is such a thing as clinging aggregates. According to this answer, for a living arahant, when ignorance is uprooted, this breaks dependent origination, that ends craving, clinging and suffering. In the chain of dependent origination, clinging aggregates would also cease.

The living arahant according to Iti 44, attained nibbana with fuel remaining (sa-upadisesa), meaning the non-clinging aggregates are still functioning like glowing embers, although the fires of passion, aversion and delusion have ceased.

Parinibbana is when the non-clinging aggregates stop functioning. This is nibbana without fuel remaining (anupadisesa) according to Iti 44.

So, the answer to this question is that upon attaining nibbana, the Buddha experienced complete cessation of clinging consciousness, but non-clinging consciousness remained functional for the rest of his human life. The five aggregates that are referred to in dependent origination is clinging aggregates (including consciousness), and not non-clinging aggregates.

In other words, upon nibbana, an arahant has complete cessation of clinging.


  QN 2: And is it possible to have complete release through jhana only
  by ceasing craving, fabrication etc without gaining insight of
  nirvana.


No. It's quite possible to cling to the pleasures of jhanas and get one's mind stuck, as seen in MN 138:


  And how is their consciousness stuck internally? Take a mendicant who,
  quite secluded from sensual pleasures, secluded from unskillful
  qualities, enters and remains in the first absorption, which has the
  rapture and bliss born of seclusion, while placing the mind and
  keeping it connected. Their consciousness follows after that rapture
  and bliss born of seclusion, tied, attached, and fettered to
  gratification in that rapture and bliss born of seclusion. So their
  mind is said to be stuck internally.


And the sutta continues about the higher jhanas.


  QN 3: Buddha stated in many suttas that five aggregates are not-self;
  but as human being we do require idea of self (identity or ego) and
  will power (self-esteem).


In a sense, you can use the idea of self in a skillful way (as long as you have not dropped self-view) as shown in AN 5.57 below:


  “And for the sake of what benefit should a woman or a man, a
  householder or one gone forth, often reflect thus: ‘I am the owner of
  my kamma, the heir of my kamma; I have kamma as my origin, kamma as my
  relative, kamma as my resort; I will be the heir of whatever kamma,
  good or bad, that I do’? People engage in misconduct by body, speech,
  and mind. But when one often reflects upon this theme, such misconduct
  is either completely abandoned or diminished. It is for the sake of
  this benefit that a woman or a man, a householder or one gone forth,
  should often reflect thus: ‘I am the owner of my kamma, the heir of my
  kamma; I have kamma as my origin, kamma as my relative, kamma as my
  resort; I will be the heir of whatever kamma, good or bad, that I do.’


Also, please see Attakari Sutta.