Well, brake pads imho are not covered under warranty and are classed as a 'consumables'. I think I would clean it all and lube it with copper grease and be happy I've not parted with and cash to Renault.

The cars BMS will control the charge rate regardless of input power

Remember the battery is a consumable item and will degrade over time/use. the 20-80 charge opinion should extend the life of the battery. However it will degrade anyway, slow charging is probably better for the battery as high power charging increases the battery temperature rapidly. There are many youtube channels who breakdown the 20/80 charging phillisophy and can explain it better than me!

Its a no brainer IMHO, I got the genuine Renault ZE 50 leather look armrest and fitted it in 10 mins, very easy. get one!