Hello, my opinions (I am not so safe with it but can do the trick):
- I see some guys ride with there bars backwards and some forwards?
-> Bar backwards make it easier to reach the bar for ride in and ride out.
- Should you master hang 10s? What about the hang 10 no hander? Should I learn this first? -> No, the cliffhanger is very unique anyway in terms of how to balance.
- Should you learn messiahs? -> No, see above.
- Does the type of seat efffect anything? Because newer street seats have a rubbery texture for gripping it for barspins? But what about a slick cover seat? -> No, this is not necessary.
- Is there a certain speed you should be aiming for or can you do this trick slow? -> Like for most rolling tricks too slow makes it more difficult. To fast is more dangerous. "Medium speed" should do it.
- Should this trick be done on complete (flat) surface not like a road or something? -> This might be better. With a big slope you will gain or loose speed quickly and this is disturbing.
- Tire pressure? Always 100? Because I run like 70-80?
-> It depends on you body mass. It should be enough so you do not bounce. In generel more pressure makes rolling easier. I would not use less than 100 psi for flatland anyway as long as you are not like 60 kg or something like that.
I cannot remember how long it took me. I needed to overcome the fear of falling. It is indeed somehow dangerous because when you fall to the front it is likely that your feet are caught on you bar for example. So keep that in mind and try to avoid this.
I found that you can balance when you press your legs/knees inwards to hold the frame/bike. This was a key for me.
Good luck!