Do you think that the employee, whatever his position, can go from being a simple executant to a creator of fertile ideas about his work?

Depending on his educational background and imaginative prowess, yes he can at-least climb up to the level of idea generation process or even try and think of more efficient and effective ways for reducing the required time for a certain task.

Yes he can. Because of the passion  he has for his work.

Of course, this sometimes depends on the nature of the person if he is interested in developing himself and improving his income and position at work or satisfied with his place

Yes, yes, because ideas and creativity are not related to the position or to the certificate, but some qualities, abilities, qualifications, etc., which vary from person to person