And as for stealing the bike,this would have been very risky.Just suppose June noticed it was missing and told someone outside the family,a farm worker for example who then tells other farm workers.
In this case they would be witnesses that the bike was taken without Junes knowledge,then the games up for Bamber,proving that he stole the bike to use in the murders.
How could Bamber know who June had told about the bike being missing?
But,no one told the police that June was looking for her bike in the days leading up to the murders,so this means she either did not notice it had gone or Bamber did indeed ask for a loan of it for Julie to use.