Is it considered a deficiency in faith to hesitate regarding wearing the niqab and to be content with the milhafah, despite being convinced of the permissibility of uncovering the face and hands?

The obligation to cover the face and hands is a matter of scholarly disagreement, but the majority of scholars who permit their uncovering have issued a fatwa that covering becomes obligatory when there is a fear of fitna (temptation or discord) caused by the woman (if she possesses extraordinary beauty) or upon her (due to the corruption of the times and the prevalence of evildoers). The jurists of the four schools of thought agree on the obligation of covering when there is a fear of fitna and the corruption of the times. Hesitation and a lack of sincere intention do not justify abandoning the niqab; rather, one should promptly wear it, keeping in mind the desire to seek Allah's pleasure and the intention of modesty. The righteous intention will follow later. As for a woman who leaves off the niqab in imitation of those trustworthy scholars whose emulation is permissible, and her motive is not whims or desires, then there is no sin upon her.