Certainly there has to be an ordered way to start a debate but whether it goes further than mere etiquette, I’m not so sure.
So the house does not believe there is a God, well, a theist could say they do believe there is a God and that would be fine, both beliefs then have equal status by being beliefs so if one had the burden of proof so would the other...
Still trying to build a false equivalence. In fact you're misrepresenting both positions. A theist, for the most part, will claim that they believe that there is a
specific God, which may well be quite a different God to other theists.
As has been pointed out endlessly, the atheist position is not the opposite (I believe that no God exists) but the position of being unconvinced by any theist arguments or supposed evidence, for their multiple versions of God.
It is the default because it is for
everything. It holds for any sort of claim, including (perhaps, especially) scientific hypotheses; the first questions are: why should I take this seriously, how do we test it, and how might it be falsified?
I claim I have an invisible dragon in my garage, and you do what exactly? Take me seriously?
But what is good is also good for the gander and somewhere an atheist bus campaign was about to commence with an exhortation to stop worrying because God did not exist.
More misrepresentation. It didn't say that god didn't exist, it was qualified with "probably", which seems to be a fair assessment of the current evidence and state of the supposed arguments.
Of course legally they weren’t allowed to put it on...
Really?
Atheist Bus Campaign.
So belief that God doesn’t exist...
Again,
you are arguing against a position that nobody here holds and that nobody is claiming is the default. Grow up and face up to what's actually being said, FFS! This ritual slaughter of straw men is just pointless.