1
The filter you found is probably not the right type.
2
Your LST is not really correct. While you are moving the plant allowing extra light to contact the lower nodes of the plant, you are not moving the top of the plant down enough to confuse the plant into generating auxins at the aforementioned node(s).
3
I feel it's VERY important to continue to move the ties.
4
The yellowing in the veins of the plant also indicate improper nutrients. High heat can explain the tip burn, but more than likly it's the nutrients you're using.
5
Go buy some nutrients intended for your plant and a new planter with even drainage, about the maximum size you can fit inside the PC(more roots=more growth), ScrubNinja is a good example of this.