Can I use my API key when my Pro has run out of fast responds?

I have the pro version with 500 fast responces, but I also have my API key linked. Can I decide whether to use the api key OR the slow responces?

I think your pro subscription has nothing to do with your api key usage. So, you should be able use one OR the other.

Ok good to know. Am I ample switch on my api key if I don’t want slow requests?

Yep. You can switch back and forth as much as you want. If you want, you can also buy more fast requests.