Ok let's slow down here.
Gentoo? after only using Mint? That's a steep curve right there. Mind you, if you know what you're getting into, Gentoo can be great for you. However, if you don't, I'd say Arch does everything you need it to do.
Saying you want customization, Arch is pretty much you building your own desktop and can even rebase it to use other Arch distros ' repos. Hell, a lot of the arch distros have GUI-based kernel builders and schedulers.
I have done minor (keyword minor) stuff with customization and whatnot, but Arch truly lets you do whatever you want within the context of not having to compile everything from source. Gentoo is that but you're having to compile any and every program from source. Not to mention, you'll also have to get very familiar with compiling flags, which are a whole beast. Since, mind yo,u with Gentoo there is no "standard" when it comes to compiler flags since for every instance of Gentoo there''s also a unique set of compiling settings for THAT Gentoo installation.
If I were you. and coming from experience of using Linux in VMs coming from Windows. Then switching to daily driving Linux. Just stick to the more normalized distros that support your needs rather than wants.
daily driving linux is a different thing to just spinning up a VM and playing around with it for a bit.