Chmaiden, this same builder promised us that they would finish our house before x-mas, then come x-mas we were told end of January, and they ended up handing over the house last week with a lot of uncompleted items. Luckily we did not give notice to our landlord because we did not believe the builder from previous experiences. I am glad the builder has agreed to increase delay damages to 250/wk, we received a pathetic 150/wk (although we knew the minimum HIA recommendation is 250/wk, we did not know we could question/contest it).
I am glad the builder has agreed to have a meeting with you on Monday - I would advice you to have your concerns in writing (before the meeting) as well as make sure that whatever the builder says is put in writing (from experience with this builder word of mouth means nothing).
Have you had independent inspection of your house at any stage? I think bringing in an independent inspector will not only help ensure you get a good quality house but it will also provide evidence that could be used in case of legal action.
Wish you the best and hope everything works out for you.