#1
Always wanted to learn how to do something like this for when I'm poor and need to be an impressive busker. Any tips on learning this or people to watch? This is the type of stuff I mean by the way.

https://www.youtube.com/watch?v=k5SpXvRbJPc
BigBoned: Hello Hung Daddy.

Hung Daddy: Hi. I'm eight and a half inches.

BigBoned: Sorry, I'm not interested in being friends with midgets. Midgets piss me off
#3
It's quite the thing (fad?) currently. I don't care for it, but perhaps because I'm too old to learn new tricks.
My slide guitar guru, the late Bob Brozman, said that all over the world various cultures used the guitar in this manner... So it's got some creds.

Bear in mind that it's rather hard on the guitar if you get too energetic. Braces can pop, tops can crack. Develop a light touch or buy a plywood instrument.
#4
First it's important to learn songs that use this style. If you haven't already learn Drifting by Andy Mckee, it's not that hard and should only take a couple of weeks if you practice hard enough, from there you can try his song Hunters Moon which is more percussive heavy.

Learn what parts of the guitar make different sounds. If we're thinking like a drummer, a good bass drum sound can be achieved by hitting any loose part of your guitar (lower bout and above the sound hole are good) with your palm. For snare, anywhere around the outside of the guitar with your fingers can work, and slapping your thumb down on the low E or A string is a very useful one too. For toms, almost anywhere on the face of the guitar with your fingers can work. Find some nice sounds and experiment with grooves.

Go check out some percussive heavy guys like Mike Dawes and Jon Gomm, both of whom have videos on utilizing your guitar for percussion. This is a rather new style (at least to most Westerners) so experiment and find out what works for you.

https://www.youtube.com/watch?v=Z1eu0cT4CkQ