Siri Kamala ji
At the risk of sounding as if I do not get your most important thoughts -- I think I do -- please let me reply to two ideas that do not seem correct. They both concern the idea of sehajdhari Christians and sehajdhari Jews.
First permit me to define a practicing Sikh as one who keeps the 5 k's, is baptized and adheres faithfully to the Sikh Rehat Maryada. Without a definition the discussion will become chaotic in no time flat.
Your analogy a sehajdhari Sikh differs from a practicing Sikh just as a Reformed Jew differs from an Orthodox Jew is actually not correct.
Or better, there is no analogy. Reformed Jews are an officially recognized denomination with Judaism. Reform Judaism has a distinct and "cohesive" identity within the World Union for Progressive Judaism, along with several other recognized denominations of progressive Jews.
Progressive Jews, including Reformed Jews, are not progressive because they are "laid back" or lenient about Judaism.
"Sehajdhari" Sikhs are not an organized denomination of Sikhs with a distinct liturgy, dogma, understanding of their scripture, or ordained clergy, as found in the various denominations of progressive or reformed Judaism.
The title of the thread suggests that Sehajdhari Sikh Federation has official status as a denomination within Sikhism. That is not the case, and it is misleading. Rather, the members of this organization have public and covert ties with different groups within sanatan dharma, a purely political move which is relevant only in India. They do not represent sehajdhari Sikhs in any official capacity.
A sehajdhari Sikh differs from a practicing Sikh according to the Sikh lifestyle: does not keep the 5 k's, is not baptized, and therefore is not a strict adherent of the Sikh Rehat Maryada. There is no "sehajdhari" interpretation of Sri Guru Granth Sahib. Nor are there sehajdhari equivalents for Sikh clergy as there are Reformed rabbis in progressive Judaism. In fact, there is no clergy in Sikhism.
Now the same can be said in the analogy:
A sehajdhari Sikh differs from a practicing Sikh just as a progressive Christian differs from an orthodox/conservative Christian.
To be Christian there are only a few basic requirements. One must accept Jesus of Nazareth as the Incarnation of "God" as "God's Son" made flesh. You must accept that the resurrection of Jesus of Nazareth was true and led to the deliverance of soul. You must accept that his birth, crucifixion and death is the fulfillment of a prophesy, to atone for the sins of humankind. You must accept the Christian Testament as the the word of God. There will be other requirements depending on particulars of Christian denominations - of which there are hundreds. As with Jews, Christian progressive and conservative denominations have incorporated distinctive public identities with unique liturgies, ordination of clergy, and theologies.
A progressive Christian adheres to the beliefs I listed above. The differences between progressive and conservative are many, but one major feature that divides them is the extent to which they depend on a literal interpretation of the testaments, old and new. There is no equivalent for this in Sikhi, and in fact, there are many acknowledged scholars of Sri Guru Granth Sahib who are not practicing Sikhs.