OEM graphite shaft typically will be 1/2" -1" longer than the steel counterpart. So the length will be already at least 1/2" longer than the average mans set with steel shaft.
Your main concern should be the flex and the weight of the shaft, being 6'3" and young, you should try a stronger flex and heavier weight shaft.
I would pull the original shaft and save them for later, reshaft the set of irons with steel shafts. It's a relatively simple job for even a home hobbyist.
If not , get your hands on another set of used golf clubs, prefer came with steel shafts and 3/4"-1" longer from the OEM. Not saying after market job could not do better, but the OEM will take the extra length into consideration and properly reduced the head weight ( lighter badge in the cavity to reduce weight ) making the swing weight correct for the standard D0-D2 for men.
Used set of irons will not set you back too much, that should satisfied your current need until later.
But that's kinda truly "owning" one of the keys, and having at least a little ability toward the other four. You can't have Key #1 but be terrible at Keys #4 and #5 and break 90 sometimes.
1-3 really help with contact, so I'd rather see you get 75% of the way toward mastering 1-3 than mastering 1 without worrying much about 2 or 3.
You can start with Key #1. I don't think you're on a bad track. Just make sure you really understand what it is. It's not really at all about actually keeping a steady head - it's about HOW you do that.
I think this might help me. may try it. Right hip/knee tends to go towards ball. I think getting the pivot less heading towards ball and right hip more going with left hip, more turning in place rather than turning towards the ball.
I dunno, lumping in a guy of Japanese descent with a guy of Korean descent when those 2 cultures have had serious animosity with each other for centuries smacks of an uncomfortable 'they're all alike'. I wouldn't go to Korea and tell them they are the same race as Japanese.