The fuel of MO is the research level questions in mathematics.

In most (regular) users' summary I look, there are much more answers than questions, as if the opposite position would be doubtful or suspect.

Question: Is it a problem if I post a lot of questions?

In my opinion it's as suspect to have much more questions than answers, than to have much more answers than questions, and in fact, in absolute, I think there is no suspect position.

Due to this suspicious belief, I think the most of my questions are under evaluated and under-attention. The ability of giving "good" answers seems much more recognized than of asking "good" questions.

Some of the high reputations users did not post a question for more than 1 year, more, some of them never posted any question at all (I don't understand why, but it doesn't matter).
Perhaps some of them have really very few questions to ask, but in my opinion, most of them retain willingly their questions, either for not being suspect or for not sharing their original ideas.

What could be "normal" is the following: for a mathematician early career, the ratio #Q/#A should be very high, for then decreasing to around $1$ mid-career, and then to around $0$ late career.
An early career great user with a ratio $< 0.1$ is far from this model.

I would be interested by a Data Explorer query classifying the users by their ratio #Q/#A for a given interval of reputation. If someone have such a query available, let me know, else I will try to program it.