Yes, you have stated your opposition, but not given any reasons for that opposition that shows understanding of what the theory actually says.
For example, when you ask what the universe is expanding into, you betray the (false) understanding that the expanding universe is like a shock wave that travels through space. Instead, it is an actual expansion of space itself.
I know the pat explanation about expanding space is not expanding into space, but I keep asking in order to show you and other BB believers that it is not logical for finite space to have no form, to be expanding into nothing. Nothing does not exist, so given that this BB universe exists, it either exists in infinite space, or nothing. To keep saying the question of 'outside' is invalid is a cop out.
It is similar to the question of what existed before the BB, if you agree there is no nothing, then it had to have began somewhere in infinite space.
I know you will then say time had not begun so the question is invalid, but it's another cop out.
The logic on which I lean is human logic, if we discard that, then we can not have a reasonable discussion. If there were a multiverse, then what would exist between universes? In this multiverse scenario, assuming there would be universes sufficiently developed whereby very advanced intelligent life could detect the BB beginning of new universes, these new BBs would be referenced to spacetime.
I will never accept BBT until I understand how and why it came into being!