To answer your specific questions:
1. If i don’t comply will they then take me to the tribunal
That’s their prerogative but if they are found to be “vexatious” then they may have costs awarded against them.
2. Will the tribunal fine me if they find me in the wrong (which I don’t think they will)
Theoretically, yes. But I very much doubt it in this case (even if they do rule against you). It’s not like you are a nuisance neighbour having parties every night. You’re a parent trying to do the right thing within the parameters of strata law.
3. Should I apply for mediation or do they do it.
Mediation leading potentially to an NCAT order would have been the civilised way for them to have done this. You could apply for mediation to stop the harassment
4. What happens if they go straight to the tribunal without mediation?
Notices to Comply do not require mediation. You will be judged on whether or not you have breached the by-law. The architectural thing is not a by-law (as far as I can see) so any reasonable member would toss that as a matter of course.
5. I was told that you can’t apply for mediation with fair trading if you’ve already been issued with a failure to comply. Is that right is has the fair trading website been misinterpreted?
I’ve never heard of this but that doesn’t mean it’s not true. Who told you this?
Also, I’m curious about your use of the phrase “failure to comply” and I wonder if the committee has issues the NTC correctly. If they haven’t, you should feel free to ignore it.
The correct form should contain the by-law (and only one by-law) that you have allegedly breached with details of how you have breached it.
I could be wrong but I think the committee has decided that mediation and NCAT orders won’t get them the result they desire and therefore have decided to go with an NTC in the hope it scares you into submission.
The architectural stuff should have been dealt with through mediation and orders (if at all).