RetroArch, Steam, Bigbox question

[SilverDragon81]

So I am in the process of setting up my emulation system on my laptop for mobility purposes and also because it seems to be the only way I can use my PS4 controllers wirelessly. I am at the moment setting up retroarch for certain systems and am having an issue where the PS4 controller doesn't always function inside retroarch but it works inside steam, I know this because if I hit the PS button on the controller it will open steams big screen window and the controller will navigate it without issue. I guess my question is: is it possible to change the function of the PS button on the controller so that it doesn't open steam since once I have everything set up I will be running exclusively in BigBox with all my steam and other PC games alongside my emulation stuff? I haven't done any testing yet with disc swapping while inside bigbox and running games through the retroarch emulator either, will using the button combo that I set for retroarch to get to the menu to switch discs interfere with bigbox at all? 

I know this is kinda all over the place but these forums have been so much more helpful than any others on the internet for me. Thanks in advance.