Salaam - Thoughts on the Naqshbandi Mujaddidi Way vs. Everyday Muslims

As-salaam-alaikum. I'm curious about how the Naqshbandi Mujaddidi approach to living the deen compares to how many Muslims live nowadays, both here and around the world. From what I saw visiting a Naqshbandi mosque, followers try to copy the Prophet’s practices very closely: wearing shalwar kameez and an imama, sitting the sunnah way in prayer, avoiding television and musical entertainment at home, keeping proper gender segregation and clear boundaries between mahram and non-mahram, eating only halal meat prepared in certain ways, growing a beard for men, and many women adopting niqab. They do a lot of dhikr and emphasize avoiding bid'ah. To me they seem very strict and sincere - really focused on reviving sunnah in a complete way. A few questions I have: - Is it better for an imam today to wear an imama instead of a kufi, or for men to wear shalwar kameez rather than a jubba, in order to gain more reward? I was told prayer behind a man without a beard might not be valid, and that imams in some countries wear traditional clothing - how do scholars view this? - Why do many scholars and local imams not follow the exact same outward practices as the Naqshbandi Mujaddidi groups, if those practices look closer to the Prophet’s example? - Are there recognized opinions from 'ulama about how strictly we should adopt these external forms? Is there room for cultural variation while still following the sunnah inwardly? I hope for some clear guidance from knowledgeable people, especially references to scholarly opinion. JazakAllahu khair for any insights.