Dont ever worry about offence I am sikh so by defination I am here to learn
I am still not clear what are you looking for expecting out the word Waheguru but i found some references on internet related to that
Waheguru is the distinctive name of the Supreme Being in the Sikh dispensation, like Yahweh in Judaism and Allah in Islam. In Sikh scripture, the Guru Granth Sahib, the term Waheguru does not figure in the compositions of the Sikh Gurus, though it occurs therein, both as Vahiguru and Vahguru , in the hymns of Bhatt Gayand, the bard contemporary with Guru Arjan, and also in the Varan of Bhai Gurdas. Guru Gobind Singh used Vaheguru in the invocatory formula - Eke Ongkaar Sri Vaheguru Ji Ki Fateh, beside the traditional Ik Ongkaar Satgur Parsaad at the beginning of some of his compositions as well as in the Sikh salutation - Waheguru Ji Ka Khalsa Waheguru Ji Ki Fateh, varied as Sri Waheguru Ji Ki Fateh.Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=969
Modern scholars, affirm that the name Waheguru is owed originally to the Gurus, most likely to the founder of the faith, Guru Nanak, himself. Waheguru is a compound of two words, one from Persian and the other from Sanskrit, joined in a symbolic relationship to define the indefinable, indescribable Ultimate Reality. ‘Wah’ in Persian is an interjection of wonder and admiration. ‘Guru’ in Sanskrit means great, venerable, spiritual preceptor and has been frequently used by Guru Nanak and his successors for Sat-Guru (True Guru) or God. ‘Wah’ is wonder at the Divine might; ‘Gu’ is spiritual darkness while ‘Ru’ is illumination brought to eliminate this darkness. Cumulatively, the name implies wonder at the Divine Light eliminating spiritual darkness. It might also imply -‘Hail the Lord whose Name eliminates spiritual darkness’ Thus the two constituents of Waheguru (Wahe+Guru) implies the state of wondrous ecstasy and offering homage to the Lord.
The attitude of wonder and total submission at the sight of Divine Greatness is prominently visible in Guru Nanak when he wrote Gurbani, for example:-
Gagan Mai Thaal Rav Chand Deepak Bane Taarka Mandal Janak Moti - In the bowl of the sky, the sun and moon are the lamps; the stars in the constellations are the pearls (Raag Dhanasri, GGS - 663)
Kete Pavan Pani Vaisantar Kete Kaan Mahes, Kete Bareme Gharat Ghariah Roop Rang Ka Ves - So many winds, waters and fires; so many Krishnas and Shivas. So many Brahmas, fashioning forms of great beauty, adorned and dressed in many colours (Japji);Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=969
Vismaad Naad (wonderous is the sound) Vismaad Ved (wonderous is the wisdom)… ( Asa Di Vaar, GGS - 462-475)
Wonder and ecstasy are expressed at the cosmic order and its mystery full of Divinely-appointed system. This last saloke concludes with ‘ Ever present to our gage is wonder. At the sight of this mystery are we wonderstruck. Only by supreme good fortune is it unravelled.’ Continuing to the next Saloke to Pauri 4, Guru Ji says:
Sikhism has a doctrinal affirmation of Waheguru, instituted by Guru Nanak. This is the Gurmantar, or Guru's creed. Note the use of mantar here for creed: the Mool Mantra can be called the Mool Mantar and mean creed.
Wahe implies wonderful, magnificent and astounding and is an objective understanding of the majesty of God. Guru means God subjectively because it comes from Gu, darkness, and ru is from light (or lightness). So God here is both objective existence and subjective expression. God then comes fully to humanity through the Gurus, and is made real and experienced through this both objective and subjective state.
God is not as such described. Rather it is God as revealed coming through the light and word of Guru Nanak, God's manifestation. However, this is still the naming of God, or Naam, and this is dependent on Gurpasad, or the Guru's grace
I still think teh imporatnce of Waheguru is its representaiomn to Formless God and may be compared to formless representatiomn to Allah BUT NOT RAM as you said as he was an historical personality and cant represent the formless god.