What should a person do if they are predominantly certain they understand the author's intent in a religious book, but they are not entirely sure? And is it obligatory for them to ask questions in such cases, or is that considered excessive if the assumptions and probabilities are weak?

Asking questions with the intention of ascertaining the religious ruling is not blameworthy; rather, it stems from piety and caution in religious matters. It is impermissible for a Muslim to perform an action until they know Allah's ruling concerning it and consult the scholars. However, exaggeration in this regard may be blameworthy if it leads to obsessive doubts (waswas) or extremism and excessive rigor (tanattu'), causing a person to doubt clear matters and abandon what is permissible. Indeed, everything that exceeds its limit turns into its opposite.