1. assuming someone, or something, created us in a certain way. what makes us/you sure that he/she/it is still alive?
Nothing, as there is not even a proof whether or not he/she/it exists other than your scope saying so.

2. is it important to you that he/she/it is still alive?
Not at all. If the being is dead, we are still alive. If the being is still alive, then he wont reveal himself to us for whatever his reasons are anyway. Our defined lifes will go on, and we should follow the path he drew, as we have always done.

3. do you rather believe that God's spirit lives on in everything that surrounds us, but god itself is dead?
No, I don't. There would be no point in that. A spirit of someone that died and trapped on earth is there for a reason, like watching over someone while not be able to show themselves (though some tend to try). God is already doing that for everyone. What would his spirit be different to what he is now?

4. can gods die?
As stated earlier, we made up the Gods with our fantasy, and thus they can "die" if nobody knows about them anymore. But it turns out to be more of a question what the definition of "dead" is here in the context.

5. can God (he/she/it) die?
Perhaps. At least it would explain why he didn't visited us in the last hundred years, yet he is mentioned in nearly every religion on earth. But I rather believe in a different theory as long as nothing is proven.

6. assuming that God is the spark that set the universe into existence, is it possible that the conversion from energy to matter is the creation itself (big bang) and thus God sacrificed himself to create the universe?
This has been answered by others.

7. assuming 6 is true, will god resurrect when the universe collapes into a single point?
As stated by others, 6 is not true.