ToME: the Tales of Maj'Eyal

I was forced to use wraithform to get away now for the first time, as i had no pd or similars.
I wanted to get through a 3 grid wall, but after two moves into it ALL my air was gone and i was bound to wait one turn and die there.
Is it intended that you should not walk through walls while in wraithform?
And why can someone incorporal hold his breath for several turns while under water and only two and a half turn while in a wall?

I think it's intended, unfortunately - I brought this up time ago.
As for consuming more air than being underwater, I think the justification I was given was something like environment pressure or just being in a wall being harder than 'just' being underwater.

Would be nice if Wraithform at least reduced this air consumption so at higher levels you could resist more...