I'm part way through retrofitting a auto dim mirror and rain and light sensor and I've got a couple of questions and I'm stuck on a few bits

I've brought a loom for the mirror from kufatec and added 3 extra cables for the rain sensor

First problem
According to elsawin the mirror gets power from fuse 31 which is already used but the fuse legend also includes the mirror but it's fused at 15 amps and the cable in the loom and mirror are very small I have a gut feeling that they are too small

The rain sensor is powered off of fuse 17 which is a 10 amp and it says it's for the headlight levelling it's ok though I have wired it with .75mm cable I'm just going to solder this onto the outgoing cable.

The next problem I've got is that elsawin says the mirror requires a connection to pin 5 of the black 23 pin connector on the power module. Problem is theres already a cable in the connection but I'm not sure if this should be the case and I just need to solder onto this cable

Last question is I want to retrofit the external auto dimm mirrors so need to connect the 2 cables from the internal mirror to the external ones

Elsawin says that there should be connections in the a pillars It the connection blocks that it stars arnt there I take it I just have To wire the cables directly to the door controllers

Elsawin tells me the pins I need to connect to on the door controllers but it doesn't state what connections I need to take out of the controller to the glass itself my wing mirrors don't have these connections in so I need to wire them from the door controller to the external mirrors. If someone knows the door controller pin outs to the mirror I would be grateful

Sorry for the long post and lots of questions but any help would be gratefully received

Cheers
Gaz