Is there any danger using two peripherals with 1000hz each one?

Danger?
Don't think so, why would it?
The only "danger" is if the device isn't prepared for 1000hz, but having 2, assuming that they're connected to differnt usb ports, doesn't increase the risk imo..
maybe someone with a more technical opinion will reply. Have you googled it?
Welcome to the forum btw!

Thanks for the answer and the welcome, and yes I searched in the web but I didnt get an exact answer, btw I'm asking this because I read somewhere that having a peripheral with 1000hz polling rate can slow the CPU and even break the USB port but I'm not sure about this; I want to increase the polling rate of my mouse to 1000hz but the default polling rate of my keyboard is 1000hz too and it seems like there's no way to lower it.

If you look at it from another perspective; it´s very unlikely if the company who made your keyboard made it 1000 hz plug-and-play while knowing people often use their mice at 1000 hz and that there is a big risk of doing so. Just like mushi I´m not a computer engineer, so I can´t guarantee that there is no risk. But if there was a risk, I would be very surprised.

Thanks for the replies, any other opinion or expert answer?

I think it could be true for old PCs with singlecore cpus and some old motherboards and most devices polling 125hz by default. But it's definitely not the case nowadays, when any decent gaming peripheral boasts 1ms polling rate at least as a possibility and many have it as a default setting. As others said - it doesn't matter if you have one or few such devices, should make no difference at all.

btw guys, what if I plug two mices at the same time? They should work completely independently right?