The reliable way to hire a tradesperson

I live in an area that includes mostly houses more than 100 years old featuring sandstone walls to the front and often exterior-painted walls to the side and rear. We recently seem to have a number of cold-calling sales people selling “free-survey” acrylic and copolymer wall and roof coating services. I would have thought they would be unsuitable for the types of house involved. Do any of these coatings actually benefit such houses?

Hi, I want to install some CCTV cameras and outdoor lighting at a height of around 2.6 metres on my house. To hide the cables, I'm planning to hire someone to cut the ceiling plasterboard, drill from the external brick wall straight into the floor void, and fish the wires through the metal web joists to the closest light switch. Is it safe to do that, and is this something a handyman can handle? Also, can the cables be routed along the edge of the void and dropped down behind the wall plasterboard, or will that gap be blocked off? Thanks!

Hey how can I fix a door frame that has a splint after kicking the door open.