I don't have any draw issues
. It was fired once when it was bare(no chimney piping) on the stand http://www.pizzamaking.com/forum/index.php/topic,11034.msg101210.html#msg101210
and it never had any problems except for heat retention but that's obvious because of no insulation. The only time smoke comes out the front is when a gust of wind blows into the oven and causes a rolling smoke wall in the entrance like at the end of the video. The one in the video wasn't bad but sometimes(most times) it's worse.
So yours isn't drawing at all through the chimney? This is going to sound obvious but did you check if there is anything to blocking it? Other than that I can't think of anything of why the chimney isn't drawing.
The bottom of the oven is insulated ala email from Ambrogi saying the only thing I needed to insulate is the top and sides. There are 3 rolls around the oven and I think it was like 1.5 rolls cut up and stuffed on top.
Depending on what style I'm going for it takes from 2.5-3 hours for full heat saturation. Every oven is different so your going to have to get used to yours. But I get pretty even bakes when the oven is preheated properly. Sometimes I would rush it and not let it soak in the heat and the bakes would come out unevenly. If your dome cracks don't get scared it happens which Ambrogi said in that same email. There are 3 good size cracks in the back of my dome and there has been no adverse effect on preheat, bake, and heat retention.
It's awesome that your putting it inside your house so you can use it all year round. Sadly I only used mine 2 or 3 times last year but that wasn't because of the oven.
Anyways, I'm really happy with mine and most like you will be with yours.