After a couple of scrogs, you'll get a feel for all the parameters and understand how it's all connected man I know that's not a satisfactory answer for someone on their first grow.
To work out how much height you've got, start with the minimum light distance at the peak of flower. That's the...
Harvested my 4x4 tent yesterday. Man I hate harvesting! Took me a good solid 10 hours to chop and wet trim. Didn't have my usual harvest buddy. My back hurts and I'm tired.
It's kinda worth it.
The fewer plants the longer veg time to fill out the space. A single plant is easier to scrog than two but it'll take longer. Three plants will be harder still. In that space I'd do a maximum of two. I think scrog works best with longer veg times. You might also consider sea of green if shorter...
You can jump out with two instructors who are not attached. They hold on to your arms and legs to help you get stable in the first couple of jumps. It's called an Accellerated Free Fall course.