[ODE] FPS Player physics: how to construct player, how to move up a staircase, etc?

[michael kapelko]

So at last i got some basic ODE knowledge.
I loaded an Q3 level, made TriMesh geom of it, so now it's like "ground".
Now I need to make FPS Player. How to make it?
I thought I can create it of two spheres connected with a slider joint 
so the player is able to sneak.
And I want to place camera into the upper one.
But then there exists a hole in the "middle" of the player, so it will 
result in strange collision.
So what is the best way do it?

And how to move up a staircase? I'm at a loss how to do it. Should I 
measure the height of a stair and then, if it's not high enough, move up 
to the next stair?

Thanks.