Wouldn’t the warranty kick in then? No product is perfect. But most have a way out. Read the warranty carefully because most of them state that if their is a problem and it's not caused by 10,000 different things, they'll replace the product. However they won't pay to remove the bad product or pay to put up new product. Basically most warranties are almost useless. Primed hardie with the intention of painting defeats the purpose of hardie. It’s a fabulous product and I don’t regret it at all Yes it's also fine as long as you are happy with their limited choice of colors.

Contrast, contrast contrast. Either go dark taupe or stone white like below, but that blue has to go.

I like the stone removed....less is more. I'm not sure I like the white railings; if you go with black windows, I would do the railings the same color like the first picture you posted. But I'd also rethink the black windows. I know they are trendy right now, but I have heard of people regretting the choice. At the very least, I would consider having the windows white on the inside.

Personally, i like the house as is. It's one of the few Tudors that doesn't look like a Tudor wannabe. Here's a before and after picture of a Tudor in my neighborhood that isn't nearly as nice as yours, but I like how they added some shingle kind of siding and did monochromatic colors.