But there is a commutative ring available, along the lines of what Mariano says.  If $k$ is a field and $V$ is a vector space, then $k \oplus V$ is a commutative ring by the rule that a scalar times a scalar, or a scalar times a vector, or a vector times a scalar, are all what you think they are.  The only missing part is a vector times a vector, and you can just set that to zero.  The dot product is then a special bilinear form on the algebra.  In the formalism, I think that everything that you wrote makes sense.