I agree with Cbiblis. If there's no formation at day 7 your temps are off. Three thermometers does not mean accurate. Calibrate your thermometers to MAKE certain of what temp you have at the top of the eggs. You want 102 measured at the top of the eggs in still air.
Yes an auto-turner helps because you don't open the bator so things stay more consistent. No, it should not be necessary, just nice. Ventilation is important after about 10 days and more so in the last five days. Without adequate ventilation chicks suffocate and die in shell.
Shipped eggs are always in ??? because postal gorillas can ruin them without breaking them, and it's very hard to tell what has been shaken to death before you try to hatch it. I've had zero hatches on shipped and everything from there to 100% hatches on shipped eggs. It's a matter of luck as much as anything else.
As to pushing your humidity up. If you have not calibrated your hygrometer. Do so now. Knowing how much it is off, is going to be important to this hatch if they go. Trying to push a hygrometer - that reads 30 but is actually 60, to 60% means you're trying to push the humidity to 90 without knowing it and that would drown most chicks in the egg.
Calibration instructions are in the "read me" file aka Sticky at the top of this forum.
I hatched in an LG first. It actually can be done, even done well once you understand the equipment. Yeah, it's not fun.
I enjoy hatching in the mini-fridge bator I built from speckledhen's instructions. Love it. So much so that I still use it even though I have a cabinet bator now. I use both.
Good luck and best wishes..