Why don't elerium walls just get the slightly more resistance, and double repair Coef? Why reduce health and massively increase resistance?

Also, the Elerium gate's model is wrong. In all cases except for the gate being below a wall section, the wall edge is on the opposite side of the wall.

Edit:

Prototypes/player/buildings.lua
The "Wall Patch" section was changed in vanilla. The "Shift" entry had a bunch of +1 or -1 applied. Not sure why, but that is the cause.

Also, the wall section itself lacks the circuit network attachment points.

Because it decreases time to repair and amount of repair-kit. This reduces the probability of losing construction-drones.

The walls will be fixed soon.

Thats why I was asking why you didn't just increase the repair Coef. That would give the same effect, but be more user friendly.