None of the keyboard shortcuts that are claimed to work actually works on my computer, nor do gestures on mobile platform. It there something I missed? Any pre-selected options or anything? I am so confused.

Check your account settings and make sure they are enabled. Older accounts have them disabled by default because they didn't exist as a setting when they were added. It looks like your account predates that point.

Mobile gestures are enabled under the themes/gestures link at the bottom of the page. Be aware that while I tried really hard to make them work and be consistent, the average digitizer quality and browser support makes them finnicky. Sorry about that.

So, I checked the settings, found the exact option I need to toggle and it works. As for the mobile one, to my surprise, it only works when I access as PC mode in Chrome on my phone. Quite disappointing, not going to lie. I thought it should work on both, or at least mobile mode, to be boasted as Mobile Gestures. Anyways, thanks for your help.

Mobile gestures should work in mobile mode. If they don't it may be that there are some interactions with built in browser gestures that are interfering.