1. Yep, that is pretty much how finger movement would have to be done. And probably other joints where practical.

2. Springs have a very poor energy density compared to other methods and this would not be practical. Relevant here to point out I have a BSME degree. Sorry.

3. EMDrive: Probably doesn't work. There needs to be a lot of evidence before it can be accepted. Photon propulsion is well known, the problem is that they are claiming a much higher force / efficiency than could be achieved with radiation pressure. Which is why it basically appears to violate the first law of thermodynamics.

4. " I came to the conclusion that the reason our mathematics were all wrong is because we adhere to a vehemently cartesian point of view " There are at least three statements in that sentence that are totally incorrect.

5. Relativistic speeds. We are going relativistic speeds - relative to the other side of the universe. It's moving away from us at nearly the speed of light and we are from it. Look up the Hubble Constant.