A magic trackpad with Mac mini, will it provide more accessibility?

For the list of gestures, invoke VoiceOver Utility, and look under Commanders -> Trackpad Commanders -> Assign Commands.
This gives you a table of gestures that you can modify, if you wish.
So far as I know, they're all equivalent to VoiceOver keyboard commands.

I love it, it makes me more sighted. I swipe down to read, as if i were on my phone. You can control the mac I would say faster. Instead of using keyboard, I usually just use it.

Use Ctrl-Option-K to start Keyboard Help. VoiceOver will announce the command associated with any trackpad gesture that you give. Escape ends keyboard help.

Trackpad gestures don't make Mac more accessible, exactly; they're just an alternative way to do anything you could use your keyboard for. I used to rely on trackpad gestures a lot because they made sense to me and I used to have a microphone that would pick up every single sound. Nowadays, it's a great alternative for automating my workflow when I don't want to spare a keyboard shortcut. I personally also find certain gestures easier to remember–e.g., go to window or application chooser. There are some gestures you can assign that require clicking + modifier key. I use these gestures to simulate a VO mouse click when needed because I can never remember the keyboard shortcut. Since someone already gifted you a Magic Trackpad, just go for it. You literally have nothing to lose.

Pretty sure it's Voice Over shift space. I don't know why I had to write that... ;) Seriously, dude, just try it and if worse comes to worse and you hate it, sell it. My only problem and i can't stop this is that I continuously bump the pad while typing. Annoying AF to be honest.