In that verses The so called God says to mohammad to give 3 months period for koffar to turn to Islam or at the end of that period kill them. How inferior of a God who says either turn to be Muslim or die. As if there is two punishments for you execution or becoming a muslim!!! Anyway, Quaran isn't a science book. The science we as it is today didn't exist even 500 years ago yet alone Mohammad to be a person who can know about it. There is lots of contradiction between Quraan's Claims and modern science. For example Quraan says "Women are the farms of men to grow their seeds" completely implying that women just provides the nutrition to man's seed. Well as we know know women has a big contribution for the seed.
Mustafa, Quraan by no definition can be called even a book. It is full of repetition, lack structural coherency, jumps from topic to topic, full of lines of scaring people. Sam Harris said you can't find a single page of Quraan who doesn't demean and threaten the non-believers.
As per your claim that Mohammad was defending himself that is a pure lie. The Jewish tribes around Madina had nothing to do with him and he attacked them just to spoil their wealth and women. The Muslim excuse is that they didn't help Mohammad on AlAHZAB war. Really? you attack someone for being neutral in the conflict? And by the way this Mohammad guy was a real person (unlike Jesus) and all his actions are recorded by his own followers. He not only did take 8 year old girl as his wife but also brought a Quraan verse that prophets wife can't marry someone else after his death. Mohammad did at 63 when Aysha was only 18. And she couldn't get anyone as husband because Mohammad banned it. If this isn't crulty then I don't know what could be.