Firstly, what is the charge at the fundamental level? And secondly does the charge have any role in creation of new matter (again at the fundamental level) or may be vice versa? Thirdly, we say that gravity deforms the spacetime around a mass, the force between charged particles is very large as compared to gravity, does the charge also deform the spacetime? If yes do we have any observational evidence.
(warning, I'm no expert here) Matter isn't created. What fundamental level are you referring to? Basically the answer is that it is neutral unless you are talking about each component but the end result is neutral. When you ask if the charge deforms spacetime the only way I would answer is to say that the mass of an atom largely comes from the kinetic energy due to the strong force in the nucleus holding the protons together...energy equals mass (2 % comes from the Higgs particle/field).
Matter can most definitely be created: https://en.wikipedia.org/wiki/Pair_production This also happens in, for example, the LHC. At the most fundamental level we currently have experimental knowledge of (i.e. the quantum level, not string theory), charge is associated to a conserved quantum number: https://en.wikipedia.org/wiki/Charge_(physics) Sort of, yes. It has to be conserved, so if positively charged matter is created, negatively charged matter must be created at the same time. I'm not aware of charge playing another, more significant role in the creation of matter. I remember reading about attempts to do just that, but I'm not aware of those attempts gaining much traction in mainstream science.
It creates electromagnetic fields, and it is the thing that reacts to those fields. It's a characteristic property of particles, and it is a conserved quantity in most reactions. As others have already said, charge is a conserved quantity, so when new matter is created the net charge before and after the creation is the same. Conservation of charge is associated with a particular kind of fundamental symmetry in physics. In the General Theory of Relativity, it is mass (or energy) that causes spacetime to curve. Differently charged objects with equal masses react to gravity in the same way, which suggests that charge does not affect spacetime curvature.
In quantum mechanics, it represents the strength of the interaction between photons which create electromagnetic fields, and the particles they directly interact with. Not specifically, other than it having to be a conserved quantity as mentioned by others here. Contrary to what JamesR said, charge has a role in causing spacetime to curve, because the presence of charge results in the presence of electromagnetic energy which contributes to curvature just like all other forms of energy. Also in Caluza-Klein theory, which Einstein personally endorsed, the presence of a compactified extra dimension of space would lead to the formation and interaction of classical electric charges and currents, but this approach doesn't really mesh with the experimentally-verified quantum electrodynamic model, although it's used extensively in String Theory.
