Has God decided one's age? If so, has He decided how he will die and by whom he will be killed?
Suppose one commits suicide, did God decide that earlier? If so, who is to blame really?
The one who should be blamed is the one who commits suicide or the killer, as Allah knows what they will do and they controls what they are doing, and Allah can prevent the killer form killing and the one who commits suicide from killing himself, but people are deciding what to do and Allah allow or prevent. So every body will be asked after death about his decisions and actions he took in life. So since Allah is knowing unseen and is knowing our behaviors even in the future and present and can prevent someone from death, therefore Allah is the one who decides when and how everybody will die.
Everone's Time of death is Fixed, But whether who will kill him or how he will be killed is destined,its still not know or no clear evidence is present in islam about it.
There is clear hadith about time of death, which is :
Allah's messenger (saw) the true and truly inspired said, (as regards your creation, 22.5) “everyone of you is collected in the womb of his mother for the first 40 days in the form of a seed, and then he becomes a clot for another 40 days, and then a lump of flesh for another 40 days. Then Allah sends an angel to write four things. He writes his deeds, time of death, means of his livelihood, and whether he will be happy or unhappy in the (Hereafter). Then the soul is breathed into his body. So a man may do deeds characteristic of the people of hell until there is but an arms length between him and hell, and that which has been written by the angel overtakes him and so he begins to behave like the people of paradise and thus he enters it. Similarly, a person may do deeds characteristic of people of paradise until there is but an arm's length between him and paradise, and that which has been written overtakes him and so he behaves like the people of hell and thus he enters it.” ( Sahih Al-bukhari and Sahih Muslim ).
But based on concept of Free will Allah has given everyone Free will till his death, based on which he will be judged in here after, so clearly Allah does not make him commit suicide , as it goes against the concept of Free Will that Allah has given us.
God has superior knowledge power He knows what will happen and he chooses to let it happen because he loves these people will die for him and for the goodness they wanted and hated those will abandon him .
And it is obvious he decided to give them both life and do what they will eventually do. This clarifies he loves and hates One will be on his throne and the other will be in fire .