Dynamic and static flexibility?

That's a really good question and I think it does matter to some extent for a couple of reasons. First is because as you get tired or if you are already tired then static flexibility can make it easier for you to still get your leg and knee up higher and more easily to kick higher. Also consider what if you are cold or tight that day. Certainly an abundance of static flexibility would make it easier for you to still be able to get your kick up there I think.

The other thing about this is you would also expend less energy in general when doing so and that can make a huge difference in any long or protracted street situation or fight I think.

To me if you are having to struggle with certain things or tire more quickly doing them because you lack static flexibility then that in itself is an overall, general weakness that others might take advantage of or that might have an impact on things.

Yes, you should be worried:

If you can kick that high, but you cannot lift that high, then it means you are relying on ballistic stretches. Ballistic stretches or activities means that the muscles are being ripped to that range. If you are young (less than 30) you might recover quickly from those tears, which will manifest as minor to major soreness over a few days. But as you get older, your body will not be so forgiving, and may take weeks or months to recover. Such stretches are inherently dangerous.

It simply means you have no strength at that end of your range of motion, and therefore cannot control your kick. Dynamic stretches coupled with isometric weightlifting can easily cure that - you just need to do it carefully and consistently over the next few months.

No it doesn't matter.