we need not any evidence or proof to believe in absent. Whatever is in Quran is undoubtedly true and no question or clarification needed in it.
However, i do want to reply on what i am quoting you.
You believe Muhammad PBUh went on miraaj 'physically'.. you also believe Hazrat Isa AS went up 'physically'. We as muslims know Muhammad PBUH met Hazrat Isa (AS) in the event of Miraaj. I want you to tell me if heavens is the physical place? can i take a spaceship and visit heaven ?
If Muhammad PBUH went to miraaj and met Jesus (AS) physically, it should be believed that heaven is a 'physical' place.
If you say its not a physical place, then Hazrat Muhammad PBUH did not go to heavens physically, nor is Jesus (AS) in heavens is alive physically..
Make up your mind.
Heaven and Hell are physical places.