It sounds like you are having a terrible time, you have my sympathy. I cannot imagine what it must be like to be in your position. It sounds so complicated, I hope you have a lawyer acting for you.
The short answer to your question re the EGM is no, lodging an appeal will not automatically mean that the meeting has to be cancelled or will be cancelled. A meeting could go ahead, and a resolution passed, but a subsequent NCAT order may render it redundant.
One option you may have is to seek an interim order that the meeting not proceed until any appeal is determined, but query whether that would be granted.
In terms of any resolution passing an exclusive use by-law making you responsible for the repairs, even if it were passed it has no effect unless you agree to it. If they passed the by-law and you refused consent (which I presume you would do), then their only option is to seek an order that you consent to the by-law, which would then be a consideration of the whole matter.
From what you have said, I don’t believe you can be made responsible for something that you did not do, i.e. you didn’t put the stairs in. Generally that means that the OC is responsible for them. However if they are illegal, then that changes things in terms of whether or not the stairs remain.
More generally re Council approvals, and this is only on the basis of what I know from my experiences with Council approvals, which would of course be different.
– a certified building surveyor can give his opinion that something is legal, but that doesn’t mean it is legal.
– the important thing is the plans that received development approval from the Council. If the stairs were on those plans, that is fine (although query builder failure to do them properly). If they were not, then you have an issue.
A couple of things that aren’t entirely clear from your posts:
– you say that this went to an adjudicator, and then in your most recent post you ask about lodging an appeal re dismissal of the application. Can you confirm that your application was dismissed?
– what was your application for? That is – what order or other remedy were you seeking?