Here is a pauri by Guru Nanak Dev ji which addresses some of these issues:
ਸਾਰੰਗ ਕੀ ਵਾਰ: (ਮਃ ੪) ਗੁਰੂ ਗ੍ਰੰਥ ਸਾਹਿਬ ਅੰਗ ੧੨੩੭
ਆਪੇ ਆਪਿ ਨਿਰੰਜਨਾ ਜਿਨਿ ਆਪੁ ਉਪਾਇਆ ॥
The Immaculate Lord Himself, by Himself, created Himself.
ਆਪੇ ਖੇਲੁ ਰਚਾਇਓਨੁ ਸਭੁ ਜਗਤੁ ਸਬਾਇਆ ॥
He Himself created the whole drama of all the world's play.
ਤ੍ਰੈ ਗੁਣ ਆਪਿ ਸਿਰਜਿਅਨੁ ਮਾਇਆ ਮੋਹੁ ਵਧਾਇਆ ॥
He Himself formed the three gunas, the three qualities; He increased the attachment to Maya.
ਗੁਰ ਪਰਸਾਦੀ ਉਬਰੇ ਜਿਨ ਭਾਣਾ ਭਾਇਆ ॥
By Guru's Grace, they are saved - those who love the Will of God.
ਨਾਨਕ ਸਚੁ ਵਰਤਦਾ ਸਭ ਸਚਿ ਸਮਾਇਆ ॥੧॥
O Nanak, the True Lord is pervading everywhere; all are contained within the True Lord. ||1||
The shabad states that God created the creation and maya (illusion). The Guru grants Grace and saves those who love God's will.
Those who love God's Will will be saved. Meanwhile, the likes of your "friend" will remain entangled in fruitless philosophical arguments.
Note: I may quibble with the translation of the first line. Some scholars think that when Gurbani talks of God "creating Himself", it's referring to establishing himself in the Universe.
If your "friend" wants to know exactly "how" God created the creation, I would say that that's a totally worthless question. Why does he need to know "how" God created the world and infused with Maya (3 qualities and 5 vices)?
Is he planning to create a universe anytime soon?
About such philosophical exercises, Guru ji says:
ਸਹਸ ਸਿਆਣਪਾ ਲਖ ਹੋਹਿ ਤ ਇਕ ਨ ਚਲੈ ਨਾਲਿ ॥
Hundreds of thousands of clever thoughts, but not even one of them will go along with you in the end.
Your Christian "friend"''s multiple questions basically just boil down to this one question.
The answer is simply that God desired to create the world (Maya) as his divine play, called "khel". Principal Sahib Singh, his his Darpan, quoted many lines from Gurbani that reference "khel":
ਲਫ਼ਜ਼ ਖੇਲੁ ਗੁਰੂ ਗੰ੍ਰਥ ਸਾਹਿਬ ਵਿਚ ਕਈ ਵਾਰੀ ਆਇਆ ਹੈ; ਪ੍ਰਮਾਣ ਵਜੋਂ
ਖੇਲੁ ਦਾ ਅਰਥ ਹੈ ਜਗਤ-ਰੂਪ ਤਮਾਸ਼ਾ
In the end, he defines "khel" as the world drama.
Note: In the pre-creation state, there was no sin, nor charity. From Sukhmani Sahib:
ਜਬ ਅਕਾਰੁ ਇਹੁ ਕਛੁ ਨ ਦ੍ਰਿਸਟੇਤਾ ॥
When this world had not yet appeared in any form,
ਪਾਪ ਪੁੰਨ ਤਬ ਕਹ ਤੇ ਹੋਤਾ ॥
Who then committed sins and performed good deeds?
ਜਬ ਧਾਰੀ ਆਪਨ ਸੁੰਨ ਸਮਾਧਿ ॥
When the Lord Himself was in Profound Samaadhi,
ਤਬ ਬੈਰ ਬਿਰੋਧ ਕਿਸੁ ਸੰਗਿ ਕਮਾਤਿ ॥
Then against whom were hate and jealousy directed?
There are many lines that could be quoted, but this sums things up nicely (21st astpadi of Sukhmani):
ਸਰਗੁਨ ਨਿਰਗੁਨ ਨਿਰੰਕਾਰ ਸੁੰਨ ਸਮਾਧੀ ਆਪਿ ॥
He possesses all qualities; He transcends all qualities; He is the Formless Lord. He Himself is in Primal Samaadhi.
ਆਪਨ ਕੀਆ ਨਾਨਕਾ ਆਪੇ ਹੀ ਫਿਰਿ ਜਾਪਿ ॥੧॥
Through His Creation, O Nanak, He meditates on Himself. ||1||
And so, the command for us, too, is to meditate on God. And that's how your "friend's" questions will be answered, if he's sincere.