I want to ask if RX480 8gb is better than 570,480 8gb for mining monero, ETH ? I know that 480 needs less power, but has no protection against heet.

Almost no difference.

So are the performance bios the same changing the 1750 straps to the 2000 straps?

No

Ok so if my Asus 570's type ends with AS13 will the AS12 bios work? It has the same memory type but different card types. My 570 is an Asus RX 570 Strix OC. I just don't want to buy the wrong one.

BIOS in question -> https://mining-bios.eu/product/mining-bios-asus-rx-570-strix-4gb-hynix-performance-timings-as12/

Thank you so much

No, it won't it, you would have to force flash it, but it might not work good anyway.

Is there anything I can do to get one of your modified bios'? Could I send you my original one?

Bit out of time, if you have more RX cards you can buy PBE 2.2 and mod all of them