Nice, next time please try to set your time like open box set up tripod close and open legs, give some dimensions if possible open and close, mount camera and you will have the time you need. Go slow with more confidence. Seems you are a bit in a rush.
I don't know. The center column seems more stout in diameter than the tripod legs. It seems to me that it would be better suited for the Sirui AM 284 CF Tripod.
It was the recommended column for the legs. I debated getting the 284 legs but I was trying to go smaller since I already have the bigger Innorel setup for birding. To be honest, I don't really need the center column but got in "just in case" for those times it'll come in handy.