At first in Genesis :between thy SEED and HER SEED, the same word is used "seed" so if you say that it refer that women will not need a man so it will be also for serpent ,the word SEED has one definition as it said in genesis 16:10 in hebrew language זַרְעֲך And if you see in oxford definition you ll find Seed mean archaic (chiefly in biblical use) a person’s offspring or descendants.And Jesus has another point of vue about serpent when he said : “Behold, I am sending you out as sheep in the midst of wolves, so be wise as serpents and innocent as doves."Matthew 10:16

About the Bible how can we know if it s from God or not ? by testing his words , we ll find many CLEAR conradictions i give you another two contradictions :
How old was Ahaziah when he began to rule over Jerusalem?
Twenty-two (2 Kings 8:26)
Forty-two (2 Chronicles 22:2)
Compare between pedigree of Jesus in Matthew and Luke

About Mohammed (PBUH) you have a wrong ideas ,you should read all the story if you want to know the truth ,and read what famous Christians say about him like : Dr.Hanz Küng,Thomas Carlyle,George Bernard Shaw,William Montgmery Watt,Edward Gibbon.........

At first i start in The execution of 800 Jews at Qurayza ,it was Saad Ibn Moad who said the judgement of TREASON and the Prophet agree with him ,which is the same judgement in Bible in Deuteronomy 20:12-16 but in Bible we find more than that in 1 Samuel 15:2-3 !!!

About the Prophet and his wives ,you should know that he said :
"The believers who show the most perfect Faith are those who have the best behaviour, and the best of you are those who are the best to their wives" so as Muslim we should treat women (mother or wife or sister) respectly , He had more than 4 wives like many prophets as Solomon ,David ..

َAbout dealing with children : As a person, the Holy Prophet (saw) was a person whom kids would love to play with. He used to get into the spirit of childish games in their company.He would have fun with the children who had come back from Aby-Sinia and tried to speak in Aby-Sinian with them. [Al-Bukhaari].