If you're gonna pull the Engineering card, you at least have to show some Engineering. Stress analysis and FEA nodal simulation using something like Patran to show deflection under load. Also, the load on the seatpost isn't static, so you have to take that into account as well. If not, then this has absolutely nothing to do with Engineering.
Nevertheless, good weight. You could have gotten a lighter post to begin with, but as far as modifications to a heavy one go, this is the only route possible
Not without vibration analysis taken into consideration.
All those are just theoretical which I have little interest. Please don't keep asking for the same thing, I have said it before (not really like to say that again), what I am doing here is a concept design with sound engineering sense which I consider clean and simple. Riding it and happy with the result is all I wish to prove to myself.
The purpose of the thread is not playing cards with you. If you think you are a better engineer, show me your works, not just talk, talk... endless talk.
Pulling card? I have my engineer registration card, I will show you before I charge you if that is what you wish to see.
p.s. It appears that you wish to start the flame. If open-fire is not your intention, ignore statement no.2, just forget about engineering, you do not need to have the necessary basic engineering knowledge to ask questions.