Main Gate Security Chain Installed, Concerns About Bathroom Ventilation & Kitchen Sink Faucet

The security chain for the main gate has been installed, thank you for arranging it. However, the newly installed chain is not large enough to cover the hole left by the old chain, so the old screw holes are still visible. Attached are photos for record.

Also, the electrician who came last time to check the bathroom exhaust fan pointed out that there is actually no fan in a certain part. What should be done about this? We are concerned that without the fan, moisture will accumulate and worsen the already existing mold problem on the walls and bathtub.

The faucet in the kitchen sink has also begun to loosen during normal use. Can someone please take a look at it the next time repairs are made?