As for what you have mentioned in the question that some Sufis say the following Du`a' (supplication) in mosques:
"O Allah, invoke peace and blessings on the one whom You made as the reason for revealing Your Mighty Secrets and the eminence of Your Merciful Lights, until he became the viceregent of Your Self Secrets...," etc.
These words and the like are kinds of exaggeration and overestimation, which Prophet Muhammad (peace be upon him) warned about in a Hadithrelated by Muslim in his Sahihfrom `Abdullah Ibn Mas`ud (may Allah be pleased with him) that he said: "The Messenger of Allah (peace be upon him) said: 'Ruined are those who are harsh in religion,' he repeated it three times."
Imam AlKhattaby (may Allah be merciful with him) said: "'those who are harsh in religion' mean those who exaggerate things and go deeply into matters which their minds can not grasp well."
Abu AlSa`adat ibn AlAthir said: "They are the people who exaggerate."
"O Messenger of Allah, Allah has ordered us to ask for blessings on you, then how to do that?" The Messenger of Allah said: Say, "Allahumma salli `ala Muhammad wa `ala ali Muhammad kama sallaita `ala Ibrahim wa ali Ibrahim innaka Hamidun Majid. Allahumma barek `ala Muhammad wa `ala ali Muhammad kama barakta `ala Ibrahim wa ali Ibrahim innaka Hamidun Majid. [O Allah, Have mercy on Muhammad and the family of Muhammad as You had mercy on Ibrahim and the family of Ibrahim for You are Praiseworthy and Glorified. O Allah send blessings to Muhammad and the family of Muhammad as You sent blessings to Ibrahim and the family of Ibrahim for You are Praiseworthy and Glorified.]"
The Prophet (peace be upon him) said, "Say: 'O Allah, bless Muhammad, the family of Muhammad, his wives and offspring as You blessed the family of Abraham. Grant favor to Muhammad, his wives and offspring as You granted favor to the family of Abraham in the worlds. Verily You are Praiseworthy and Glorious.'"
"O Messenger of Allah, Allah has ordered us to ask for blessings on you, then how should we do that?" The Messenger of Allah kept silent, and then said, "Say as I taught you: Allahumma salli `ala Muhammad wa `ala ali Muhammad kama sallaita `ala ali Ibrahim wa barek `ala Muhammad wa `ala ali Muhammad kama barakta `ala ali Ibrahim fil `alameen innaka Hamidun Majid [O Allah, Have mercy on Muhammad and the family of Muhammad as You had mercy on the family of Ibrahim and send blessings to Muhammad and the family of Muhammad as You sent blessings to the family of Ibrahim among humankind for You are Praiseworthy and Glorified] and peace as you know."
These words and others, which were authentically reported from the Prophet (peace be upon him), are formulas that a Muslim should learn and use in invoking peace and blessings on the Prophet (peace be upon him) because the Messenger (peace be upon him) is most knowledgeable of what is proper to be used in invoking peace and blessings on him. He is the most knowledgeable of the words that should be used in the right of his Lord. Exaggerated and innovated words, which bear incorrect meanings, such as the words you mentioned in your question, must not be used, because of exaggeration, which may be interpreted by incorrect meanings.
But if they answer you not (i.e. do not bring the Book nor believe in your doctrine of Islâmic Monotheism), then know that they only follow their own lusts. And who is more astray than one who follows his own lusts, without guidance from Allâh? Verily Allâh guides not the people who are Zâlimûn (wrongdoers, disobedient to Allâh, and polytheists).
We ask Allah for safety and not to follow our whims. We ask Him to make us, as well as our Muslim brothers and sisters, among those who respond to Allah and His Messenger, who glorify His Shari`ah and who warn people against Bid`ah (innovation in religion) and whims that violate His Shari`ah. Allah is the Most Generous. May peace and blessings be upon our Prophet Muhammad, his family, Companions and those who follow him righteously.