Questioning vs. Doubting

Genuine questioning is more related to inquisitiveness, openness to explore, to see what is really there.
Although questioning also affiliated with doubting and might involve some senses of doubting.
Doubting and questioning aren't exactly the same thing.
To doubt something involve a sense of disagreeing; there is a  sense of preexist or immediate judgement even before you begin to explore.
To doubt can be a healthy thing, a vital and beautiful ability to have.
But it also can be harmful when it is overdone, i.e. when one establishes the habitual tendency to doubt everything and anything.
In other words, the mind become so habituate to doubting that it loses its ability to see things with a genuine open mind.
And as a result, nothing is permitted to get it.