I'm pleased for you that I've been proved wrong, so far, in terms of any cracks. I guess the biggest risk was during the first few firings, and as you're got past those, and not reported anything, you might be home and dry in the long term. I hope so.
As for style and 'artistic merit', your tandoor really should take first prize. I never fancied an ugly lump something like some of the others, in my back yard, but your design really does look good, quite apart from seeming to work well.