Dear Friend
If you are asking in YES AND NO format then the simple answer is NO
Guru Nanak was NOT GOD
Instead he was at Peak state of counciousness where one is one with GOD and so can any other Human reach the the state , the same as Guru Nanak .
About THE ABOVE TWO QUOTES There is PROBLEM IN TRANSLATION AND IS GIVING THE DIFFERENT PICTURE
If you know any indian language like Punjabi /Hindi then you can appreciate that the WORD LORD INCARNATE IS THE INTERPRETATION OF THE WRITER and not mentioned by Guruji
I would recommend to follow Translation given
As I have understood that in Gurbani Guru JI and Bhagats have refered to Guru the perfect Guru and that Guru is AKAL PURAKH Himself and I firmly believe that Even for all the sikhs the Guru is AKAL PURAKH HIMSELF which has manifested in the world as SHABAD GURU that is the way it has been commnicated to the Human beings and our GURU Ji were in real sense of Guardian of the SHABAD guru and so that it could be preserved and propagated as SHABD Guru in form of
Guru Granth Sahib to all the Humanity.
To aviod such confusion further in your Understanding of Gurbani I would suggest the TEEKA BY PROF. SAHIB SINGH JI but unfortunately it is in PUNJABI .
THIS THE COMPLETE VAAK HERE
ਜਿਸ ਦੀ ਸੇਵਾ ਕੀਤੀ ਫਿਰਿ ਲੇਖਾ ਮੰਗੀਐ ਸਾ ਸੇਵਾ ਅਉਖੀ ਹੋਈ ॥ਨਾਨਕ ਸੇਵਾ ਕਰਹੁ ਹਰਿ ਗੁਰ ਸਫਲ ਦਰਸਨ ਕੀ ਫਿਰਿ ਲੇਖਾ ਮੰਗੈ ਨ ਕੋਈ ॥੨॥
In this VAAK of Guru Sahibaan , are advising
That if you serve somebody and still you dont get liberated then that service is Dificult or in other wise uselss as you will not be liberated
in second part Guru ji Advises to Serve Perfect Guru AKAL PURAKH so that your cousisness is elevated to level of liberation where you can precive ( DARSHAN )all prevading god and get liberated .
Jatinder Singh