Hi there ! I am the author of the video in the second post. Just to clarify : the only "cheat" used was mechjeb to see useful numbers like the altitude to ground and the orbital period. The wheels on my gate were of course used at the beginning to put it exactly at the equator. It was a huge pain in the a** to land and manoeuvre it due to the low gravity, that thing was just asking to tip in any direction. Next to that adjusting the orbit was easy. Your challenge is definitely achievable. The larger diameter of my pinhole made it easier to cross it 15 times in a row without corrections. I guess if you just need one pass trough it you can make it much smaller.