That is a falutly comparison. You oren’t omniscient and omnipotent, whereas God (supposedly) is. That is what makes God responsible for people who do evil things. In fact, if you accept the idea that God create the universe and everything in it, then God created evil, so yeah, I’d say He’s responsible.
Huh? It’s a gift and a loan? Those are mutually exclusive. Gifts, by their very nature, do not have to be returned.
I’d regard suicide due to despair as an immoral act - it is an implicit condemnation of the world and everyone in it as worthless. It is the affirmation of a belief that there is not one piece of beauty worth seeing, not one person worth knowing, not one ideal worth living and fighting for. The circumstances driving someone to suicide may explain the action, but they do not justify it.
I do not see it as something that can realistically be prevented by law, I believe it is ultimately your own choice whether you commit suicide, but this does not make it a moral action, and confronted with someone at the edge of a cliff I’d say the moral person would be the one who pulls them back from the edge rather than the one who sits back and says, “your choice,” or even gives them a push.
On the matter of the terminally ill, I find that a less clear cut argument. It may well be the case that there can be a point reached where there is no life/world for them to reject - all that lies ahead is misery and pain, or where they live only in a drug induced stupor. In such a case I have difficulty regarding the action as immoral - it is less a condemnation of the world, and more an acceptance your time in the world has come to an end.
As regards assisted suicide for those with crippling illnesses, I find that a more difficult argument on purely moral grounds, but I’d be inclined to oppose legalising it on practical grounds.