I’m not sure about Razer sorry. I only know Ducky and Keychron typically use switches with Cherry stems.

Others have mentioned Keychron and Ducky already but I just want to mention you can get the pudding keycaps separately for cheap off AliExpress.

A compact 65 for work, a slightly larger 75 for home along with a 40 to play games or experiment with.

Looks amazing. Will you release the gerbers?

Looks great, where are the key caps from?

Great colour scheme

Yes and no. For a cable with just different connectors, the kb or host would need to understand how to convert to the right protocol, PS2/XT/etc. The voltages are the same though I think (5V).

Something like this would be needed https://github.com/No0ne/ps2pico