I'll take a shot...
First, you have to use your power of reason and consider what else the Bible says on the subject, like some of the Scriptures which have already been cited to you, like Eccl 9:11 and the account of Adam and Eve, where they obviously were given that right to exercise their free will...
Understanding your reference of Eccl, 3:1-15...Solomon was not saying that births and deaths are predestined...his point is that births and deaths, like many things in life, come in endless cycles...life will have its ups and downs....“There is . . . a time to weep and a time to laugh,” says Solomon...such repeated patterns and unforeseen calamities, Solomon shows, are common to life, to “every affair under the heavens.” Ecclesiastes 3:1-8; 9:11, 12...his conclusion is not to get so swept up in our daily affairs that we overlook our Creator...
Matthew 10:29... Jesus’ point....if Jehovah places such value on a single sparrow, of how much greater worth is a human...as Jesus explained, Jehovah knows every detail about us...
Here is another way to think about that scripture...just think about the hope of the resurrection...how intimately Jehovah must know us in order to re-create us...He values us so much that he remembers every detail, including our genetic code and all our years of memories and experiences...also in his teaching, Jesus often used contrasts, reasoning from the lesser to the greater... the point of Jesus’ words about the sparrows becomes clear...if God cares for these tiny birds, how much more will he care for humans who love and worship him...the fact that He knows when a sparrow falls is hardly in support of proving He causes them to fall...He is simply aware of all his creation and He cares...