I am going through your center video once now, and I will write down my thoughts as I go.
1:22 "first finding a center with a 1x2"
This will not automatically get you the easiest/best center to solve. It is often best to look at 1x2 blocks elsewhere on the cube (blocks of "edges" and "corners"). There's really no set method for finding a low movecount first center
1:50 "that gives me a 1x2 block"
it's a 2x2 block
2:34 why the frick did you use a slice move to insert the last bar on the first center?
You wait until 3:38 to explain that you "can't just leave it there" while solving the 2nd center, but you had already solved a piece of the 2nd center before that; shouldn't you have explained it then?
5:57 Protip: r U' r U2 r2 instead of all those moves you did
6:30-ish. Here is how I would solve that Last 2 Centers: U r' F2 r F U' r U' r' U r U2 r'. Several moves less than yours. I really have no idea what you were even trying to do, I saw a lot of wasted moves.
6:55 This one doesn't make that big a difference, but I have to point out that commutators are not necessary here; two centers can be swapped quite intuitively with Sune type stuff.
Your solution: F' U2 r U' l' U r' U' l
My solution: U2 r U' r' U' r U2 r
Yours is one move longer (in HTM), and is 4-gen, while mine is 2-gen.
Will go through your edge video soon
