Not sure which filter you mean, but if you mean the circular filter in the dust bag compartment, you just twist it off and clean it using a brush.

If re-pairing is required on each restart, I would assume something is wrong with the motherboard, but impossible to definitively say just from the fault description.

In my experience, error 13 (Charging error) is caused by one of 4 things. Robot's motherboard, Robot's battery, dock's motherboard or the dock's PSU.

The robot's motherboard is one possibility, but it is not the only one.

No, because we can no longer source them either.

You grab it at the front or sides and pull it off. The latches aren't super strong, and have some flexibility to them, so you're unlikely to break them.

Counter clockwise, my bad. Fixed in the guide.

Hello!

The LED cable you're referring to is only present in the S7 MaxV model (the one with the camera).

I plan on creating a separate teardown of it once I get the time.