A:AnswerRazer Synapse software allows you to map the button to keyboard keys and combo keys so yes you can do it. If you set each button for a combo key. But you have to be running synapse in the background for it to apply. I disabled the software at startup and none of my button mapping changes were in effect until i launched it. Just something to be aware of.
A:AnswerShort Answer: Yes, but with limited game support.
Both the Xbox One and Playstation 4 support mouse and keyboard. Microsoft announced direct support with Razer mice and keyboards in Sept of 2018 and Sony has long supported USB mice and keyboards, but it is still up to the individual game developers on whether to incorporate m/kb support. Here are links to a list of supported games:
Xbox One mouse/keyboard supported games:
https://www.windowscentral.com/list-xbox-one-mouse-and-keyboard-games
Playstation 4 games with mouse/keyboard support:
https://www.psu.com/news/how-to-use-a-keyboard-and-mouse-on-ps4-and-which-games-are-compatible/