I, too, use a 64gig stick and I have not come anywhere near to filling it. My average OS with Home storage is around 10gigs to a max of 20gigs. I say that, while I have never reached twenty gigs but for safety…
I really think 64gigs is plenty fine for regular use and exploring the system and getting a feel for it.
Zorin on USB should work with all your drivers. As a bootable “Try out” medium, it essentially is using the same modules that it would be using when installed. In some case, a more generic module or driver is referenced when used as a Trial instead of as an installation. This can cause some slowness at times. It’s not overly common. And it is less common that something works in Trial but does not work on installation (and the other way around)- That happens not due to drivers as much as due to Configuration.
This is why sometimes the simplest fix for problems that come up after installation is to remove the home ~/.config directory, defaulting back to the same configurations that would have been used during the USB run or Right After a recent installation.
I do use Zorin on USB for testing. I Do Not Use Gnome, but sometimes I need to test something IN Gnome and it is easier to do it on a USB. I Do the same with Zorin Lite. And sometimes, I am a wildman and load up entirely different desktops and distros for testing things as well. Using Zorin Lite on USB is a breeze. although slower, it feels very much the same as using it as Installed.
Zorin Core… is a little more nerve-wracking. I rarely have Technical issues with it, though. Zorin Ultimate is heavier on what it carries with it, I wouldn’t want to use it on a Persistent USB, Lite or otherwise.
For Fun, a person can load up Antix on a USB and watch magic happen. It doesn’t matter what you plug it into, it runs blazing fast. Desktop Environment is very simple and meager, though.
It kinda reminds me of Puppy Linux, really.
For Audio- we can try troubleshooting that in much the same manner on your persistent USB as on a full installation.