I'm not sure what you mean by medium here, but I believe I can still provide an answer to your question.
A fuel-thruster works by pushing the fuels reactants back and thus pushing the thruster forward. A human cannot swim in the vacuum because there arms do not push anything back. In water, a human can swim by pushing water back and thus pushing the human forward. By your use of words, I guess you can consider the "fuel" in this case as a "medium" for the reactive force.
In answer to your first question, which I interpret as "does a force require both something that caused the force and something that receives the force", the answer is yes. However, we can write quantities, such as the potential, that only depend on a source.