Yo. :smokebuds:
The soil level thing happens to a lot of people I see until you get used to it. When you initially fill your pot you gotta kinda push it down some, not pack it in there solid, but just tighter than just pouring it in. I usually tap my Airpot on the ground or wherever I am filling a couple times as I go along. For now you can just leave those leaves. They'll probably die off anyway from getting nute feed on them and very little light, so I would just let them roll.
You'll see what looks like tiny white hairs pop out of the nodes, generally the top one first. That is showing sex basically, then it will continue to throw out these pistols all over at all the nodes and bud sites, this is pre-flower, and that just progresses to full flower after a few weeks, give or take. I don't use HPS/MH, but I don't believe there is a set time to switch really. Somewhere shortly after pre flowering I would think.
You'll encounter various phenotypes from one strain. Totally normal, and looks like you got three of em.

One bushy, one with a main stalk and little side branching as of now, and then the tall one.
Take care, Calv. :smokebuds: