Matter, no it is not. Matter can be created with energy. When this is done you create matter and anti-matter. If they collide they destroy themselves and become energy again. I believe they also have a decay rate of their own as well. Which is why they think there is hardly any anti-matter around, it decayed faster than matter. That allows us to live in a matter world not anti-matter world or worse no matter.
The famous equation E=MC^2 gives this relation. As far as we know energy is eternal though. This is not to say matter cannot last forever, just that nothing assures it will.
I am unsure about space and time. It depends at how you look at these. We are in an expanding universe, so it seems the current space we live in will exist forever, but constantly expanding. This will lead to what some people call 'the inevitable heat death of the universe.' Since there is only so much energy to warm the universe, eventually this energy will become so spread out across the expanding universe everything will cool to essentially absolute zero. At this point there wouldn't be enough energy in a given area to do anything. If we were in a contracting universe however, it is believed the universe would collapse in on itself creating a black hole, or possibly another big bang, at witch the cycle begins again.
Time is just another dimension of space as we know it. So looking at time (or space) pre-big bang is pointless to us. But as long as the space exist why wouldn't time.
Photons are created and destroyed rapidly so they are not. A proton is sub-atomic matter, it is one of the components that creates atoms. But it is matter therefore what is stated above goes for this. And Forces are based off of other things. Either a matter, energy, or matter/energy interaction. So as long as what causes them exist then yes. But the forces themselves are constantly created by their sources.
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