Having a hard time with the controls

[Douzeju]

So i found out that you can almost exclusively play with the mouse: you tilt your bird to the right, left, up and down when flying, and you fly forward with LMB.

But i don't really get what RMB does.
Is it a kind of brake ? when you fly it almost always stops you, but when on ground, it helps you take off (if you don't tilt too much to one side or another though). What's the purpose of this command ?

Also, i feel having the arrow keys or WASD as additional controls when on the ground is kind of superfluous. As of now, LMB doesn't serve any purpose on the ground cause i couldn't find any situation in which it would be useful. Most of the time you just crash if you try to LMB on the ground x)
What if LMB would make you walk ? you could then ditch the arrowe keys altogether, and turn left or right with the mouse.

Maybe the arrow keys were designed for those who want to play with a keyboard only, as you can also tilt to one side or another with them when flying. But they have a totally different role on the ground, and they don't act the same way as the mouse would. Is it on purpose ?

Didn't try the controller for now, bu i'll probably sometimes soon :)

[Noodle]

The controller is much easier for me so I'm going by that.

The "break" control you talk about is exactly that. It also allows you to fly backwards, which is why it makes it easy to take off. You can just fly directly up (backwards) before going forward.

Keep in mind it is Early Access, really just made for relaxation right now.

(Literally just saw the post date of this as I was writing but I'll post it anyway for future reference.)

[Douzeju]

Haha no worries, thanks for the answer, i actually found out how it worked not much time after I posted this :)
And i do know it's early access, actually, that's exactly why i posted this: to improve the experience before the real release.